I agree with Assassins Creed. I refused to buy the second one because of the first one. But my roommate bought the second one and it actually looks pretty fun. I am considering of buying brotherhood just because of that.
I usually get bored of GTA games after a while and it takes me a year to finish those games just because I have to take a four month hiatus every three days or so.
The Dig. The idea was good and the story was okay, but the gameplay was infuriatingly slow. There were times that I literally screamed at my computer because I realized that I had forgotten to pick something up in one of the rooms and knew that it would take at least ten minutes of plodding from room to room just to go get it.