The worst game I played this year was probably The Transformers (PS2) game from 2004ish.  I was kind of bummed because I really wanted to play it when it came out and it got decent, not great, reviews.  But suffice to say that game did not withstand the test of time.  I made it to the second "zone" and threw in the towel.  It just wasn't any fun, but I really wanted to like it.
 
As far as new games go, Bionic Commando was probably the low point for me.  That was another game that I really wanted to like, but it just wasn't very good and the whole time you're just sitting there thinking of ways that they could have made the game better.