I agree with GTA4 (Oscar worthy story was such a joke) and Black&White (so begins Molyneux's overhype machine).
I would add:
Assassin's Creed - Wow, so boring after 2 hours. No variety at all.
Crackdown - Wow, so boring after 2 hours. The demo was so awesome, then you buy the game and it's basically the demo, except you can save, there's no time limit, and the entire map is unlocked.
There are probably others, but those are the ones that stick out in my mind.







