I've only had one game get bugged, but it got really weird. He was engaged to a married Sim and could not break up with her. No quests were showing up in France, and sometimes he would be frozen in place. I ended up deleting him, and all was fine.
Overall, though, I think it is a good game. The tomb-exploring is a new twist to the game that works really well, but it is not as sandbox as the rest of the game. (traveling, that is)