My award would go to a little known game called Zombieville. Oddly I suffered through this mess for many hours as I found it strangely intriguing for a good while. The randomness of the bugs seemed to allow for more progress at different sittings. The bugs seemed almost to add a new element of challenge to an already difficult game. My experience can best be summed up by the following review.
So say you, what game "bugged" you the most?