First of all you must clear if you are talking about the 1.2 patch only or the Apolyton Pack with CD's mod.
For the Original game:
The Labyrinth is very strong but only in games that have big map or many good...
The London Exchange is in my opinion the strongest and then the Labyrinth.
Also very strong the Edison's Lab.
I won't talk about the Sensorium,or the AI Entity because the come up late in the Game and I think in most games the winner will be sertain.
For Apolyton Pack:
Laburinth only if you can build 2-3 monopolies.
The London and the internet.