Master of Magic

[N35t0r]

typing 'exit' on the command prompt

[edit:]

Alt-tabbing to dosbox's control screen and closing that one works as well, IIRC.

[Elok]

Thank you!

[Solarius Scorch]

MoM was a fantastic game. Not a perfect game, far from it; it was unbalanced, had various design issues and had poor graphics (even for its times). However, the sheer awesomness this game was enough to make you forget such details and happily raid magic nodes with armies of your special characters.
Yes, I still play it.