[SIZE="3"][B][U]Introduction[/U][/B][/SIZE]

The following Article is about the individual usefulness of traits for ffa and Ironman type games (for description of game types see here) and how you have to adopt your game style to those traits in order to put them to full use.
Some traits are only useful in certain situations or on certain settings, e.g. organized. Others require a very specific game style to be of use, e.g. philosophical. So there aren't just good or bad traits in general, but you have to decide by the settings and the game style you want to play. Also u may be playing a game with random leaders, so you have to fit your game style to the traits you got, not the other way round. For this it's important to be familiar with the possibilities of each trait, not only your favorites.

[B][U][SIZE="3"]Financial[/SIZE][/U][/B]

+1 commerce on every tile, that already gives 2 or more commerce.

Financial gives one of the strongest long term boosts to your economy. The big point here is, that fin allows you to get more commerce of your land, then it originally provides. The bonus of fin is not bound to a specific point in the game, but will work from the first to the last turn, thus making it very useful plus providing you with a lot of flexibility.
Someone may build his libraries faster with creative or get his cities going fast with exp, but, presuming you get the same amount of land, in the end you have the same buildings and cities, but just get one more commerce of each tile.

The two major points of use for fin are working cottages and water tiles. The big point about water tiles is, that fin is the only way to “improve” water tiles, besides certain building everyone can build. Because of this fin becomes disproportionally strong on maps with lots of water like Archipelago, Islands and Hub. The effect on cottages of course should be used, so when you are fin you should be playing some kind of cottage economy. While fin is making cottage economies terribly effective it also kind of binds you to using a cottage economy, which can be a disadvantage.

[SIZE="3"][U][B]Expansive[/B][/U][/SIZE]
+25% production of worker
+100% production on granary and harbour
+2 health in each city

Well, Expansive is of course for expansion. Not much of a surprise.
Expansive is one of several expansion traits, but definitely the most useful of those. The bonus on workers is pretty useful, but you have to understand, that this is only on hammers, but not on food changed to production. Since you will often be making your workers with food overflow this isn´t too imbalanced.
What makes expansive really useful is the 100% hammer bonus on granaries reducing the cost of a granary from 2 slaved pop to 1 slaved pop. This enables you to grow a new city to pop 2 and slave a granary, thus doubling the slave-production output of that city, providing you with a big boost. With expansive u can plant a new city, connect one food tile, slave a granary and you have a well running city with 3-4 worker turns investment.
As you may have noticed exp should not necessarily cause you to build more workers, but can actually enable you to manage with less, speeding up your expansion even further.

[B][U][SIZE="3"]Philosophical[/SIZE][/U][/B]

+100% great people points
+100% production for universities

Philosophical is one of the strongest traits in the game and the second big commercial trait besides Financial. But it also is the most difficult to play and in its effect very dependent to how you use it.
The big point of philo is of course the bonus on great people points. The production boost on universities is nice, but nothing important like all production boosts on buildings in mid and lategame in Ironman. This is because on a game lasting 200 something turns, it doesn't matter much, if you get something some turns later, as long as it does not directly influence your early expansion like the expansive trait for example. Of course it helps, but there are far more effective bonuses available. The bonus on Universities is actually one of the better ones, because when having teched Education you need them for Oxford as soon as possible. This can make some difference in the race for Taj Mahal, Statue of Liberty etc.
Now the bonus on Great People can only be used, if you are getting any kind of Great People points, which does not happen by itself.
There are two ways of getting those points. First is working specialists in your cities. Without Philo you can usually only get two great people with just working specialists in your cities before the lategame, if you don’t use Pacifism or National Epic, which both have to be researched and dont necessarily are on your tech path. Also whether you can use Pacifism is dependant to how much military you currently have (need to have) due to the additional significant unit upkeep cost of that trait. National Epic only helps in one city and requires a fitting spot to be effective.
With Philosophical you will get far more great people from working specialists in cities, because you can get some in other cities then your national epic city as well. This enables you to use a GP rotation system, making GP in various cities each one in turn, while the others collect GP points again. Also in lategame with Mercantilism and possibly Statue of Liberty or food overflow from corporations GPs will pop automatically, providing you with enough of them to run the necessary golden ages.
This alone makes Philo a useful but not powerful trait. What can make Philo the strongest trait in the game is the combination with wonders and a super city specialist economy. For this you have to grab as many of the early wonders as possible. Which actually doesn't matter that much, though of course Artemis Temple and Great Library are especially good.
These early wonders will automatically provide you with a constant Great People flow throughout the game. Best is if u got a good production city early, so that you can build those wonders all in one city.
Now you will most likely pop Prophets, some scientists and maybe an engineer. These great people you immediately settle in thet wonder city. Since these GP provide you with more hammers this leads to an exponential effect: hammers => wonder => great people => more hammers => more wonders => more great people => more hammers => ...
Besides getting tons of wonders with some nice effects all the settled GP will produce huge amounts of science and gold. Later you put University of Oxford and either Globe Theatre or Wall Street into that city. This way just like with fin you can gain far more commerce from your land, then it originally provides. A single city working about 15 tiles will make the commerce that usually takes 4-5 cities to get. This tactic is especially strong on small maps. When everyone is having 12+ cities the bonus of fin working on all those cities will outweigh the boost of Philo on ur single wonder city.
This leads to the big problem of Philo: Its use is very dependant on circumstances. For a wonder economy wonder ressources are very good, if not vital, those you don't always get.
If u have to wage war Philo wont help you, while with Fin you will still get better tech from your cottages while slaving units. Also the use of Philo varies strongly with map size. The lesser land you have, the more effective Philo becomes in comparison to other traits.

[B][U][SIZE="3"]Imperialistic[/SIZE][/U][/B]

+50% on production for settlers
+100% on great general points

Imperialistic is another expansion trait, probably the second strongest. +50% on settlers is pretty much and will enable you to slave a settler after preproducing it for one turn in any pop-4 city, while without Imp, you have to preproduce 26 hammers into the settler, which can take some time, depending on land situation. Thus your cities don't necessarily need mines or anything to get expansion going.
Also Imp provides you with very interesting options of making very early settlers. When you e.g. have a pop-2 city with plains cow and plains copper, you can easily just produce settlers there. In addition chopping a lot early settlers becomes really attractive as imp.
Being Imperialistic forces you to play slightly different from Exp. Probably you will end up building granaries pretty late and slave little. Settlers are easily made with 2 chops and some production turns or just produced in cities with good ressources. Imp should also change your settler/worker ratio significantly since it's often more effective to first plant a city and then get the workers to improve it, or at least have less workers when planting.
Still Imp is clearly second to Exp, because the boost from granaries is just too strong for a fluent expansion curve.

[U][B][SIZE="3"]Creative[/SIZE][/B][/U]

+2 culture/turn in every city
+100% production for libraries, theater, colosseum

Creative has two aspects, both being valid, but only in combination making it really useful. +2 culture/turn make it an expansion trait, sparing you the cost of monuments and enabling you to plant the spots you want without the problem of cities only starting to work after having spent 10 turns on building a monument and waiting for expansion. This can be especially useful when needing a strategic resource fast.
The production boosts are only interesting when you want to build libraries very early, which is the case when being Philosophical and wanting to go for early scientists. Both traits together make for a very fast Academy in capital giving your tech a nice early boost. Still you should be careful with investing too many early resources into this, because delaying early expansion can prove fatal. More on this with economy strategies and game types.

[U][B][SIZE="3"]Organized[/SIZE][/B][/U]

+100% Production on courthouse, lighthouse
-50% civic upkeep

This is a very tricky trait. On standard ffa settings with noble difficulty, standard mapsize and room for about 10 cities it's pretty useless. Civic upkeep doesn´t rise to noticeable amounts before lategame – and you never pick anything just for lategame.
City maintenance costs aren´t dramatic either, so getting courthouses a few turns later won't hurt you. However when playing with higher difficulty or on smaller maps, city maintenance rises a lot faster when expanding. Now it can be interesting to have Org to get courthouses early in newly planted cities keeping up your science rate. This is most interesting when picking Org together with Holy Rome´s improved Courthouses (read about the Rathaus here).
Additionally higher difficulties rate down expansion traits, which Org often has to compete with for being picked, because you don't want to get cities as soon as possible, when they will ruin your economy. This makes Org an interesting option from Monarch difficulty upwards. With higher difficulty civic upkeep also becomes a more relevant factor too. Still Org is only useful on large maps with room for at least 10 cities.
Of course when being Org you should get code of law rather early.
[U][B][SIZE="3"]
Industrious[/SIZE][/B][/U]

+50% production on wonders
+100% production on forges

Of course interesting point are the +50% production on wonders. This will enable you to decently build wonders without wonder ressources. Anyway there is a problem. Some people will always have the wonder recourse and still be faster. But if you have wonder ressources you don't really need Industrious. So this trait is only really useful, if you go for massive wonder spamming, but whether that is possible depends on your opponents game style, resources and traits. Thus it's much of a gamble.
Industrious is one of the traits you are probably never going to pick on your own, but can come in handy, when getting them via random leader. There is much worse – and nothing really to say anymore.

[B][U]Spiritual[/U][/B]

+100% Production on Temples
No Anarchy

Spiritual isn´t good, isn´t bad and doesn´t really change much. It's a trait, that's useful, but nothing you are going to pick of your own choice. Also you won't change much about your game plan, except maybe switching civics once or twice more often. Of course Spiritual favours caste system phases for GP making, since you don't need a Golden Age for those, but it's no necessity.

[B][U][SIZE="3"]Charismatic[/SIZE][/U][/B]

+1 happiness
+1 happiness with monument
-25% EP for unit promotion.

Ah, finally we have hit one of the most useless traits there is for ffa. To say something positive: With the extra happiness you can go Math before Monarchy in a few more situations.

[B][U][SIZE="3"]Aggressive[/SIZE][/U][/B]

Free strength 1 promotion on melee and gunpowder units.
+100% production for barracks.

Just like Chm, Agg doesn´t help with buildup, so it's not useful in general. Still there are some situations on close open land maps where you will be grateful for being Agg. People are less likely to attack you, and most of all Agg opens up the possibility for killing someone with an Axe/Sword stack if you dont have enough space.
If you want to “use” Agg actively, attack someone with Axes/Swords or Maces. Anyway don't attack someone just because you are Agg. Just use it to have an easier war.
[B][U][SIZE="3"]
Protective[/SIZE][/U][/B]

Free city defense I and Drill I promotion.
+100% production on walls and castle.

Erm... Protective makes it less likely that you are going to be attacked early... else... ask random generator for something better.

PS: Since there was already a misunderstanding at fastmoves: The order is NOT a ranking, but random.