I am having the exact same problem. Like you said, I choose a town and about a quarter of the way it crashes, saying "Sims 3 has stopped working." Exactly what happens to me.
I've tried everything, uninstalled custom content, even uninstalled Seasons but even without the expansion pack, my game STILL doesn't work. It's frusterating and now I can't play my game...at all.
I know your pain -_-
