The title pretty much sums it up.
1. Killing Floor - most critics said it was boring, the graphics weren't good and the voice acting wasn't all that great. I don't know what their problem was, I really liked the monster sounds and looks. The maps are pretty well designed. The graphics look just fine to me and are actually pretty good for it's 2009 release. I love the heavy metal/hardcore DnB soundtrack. And I just overall had fun with it.
2. Saints Row 2 - The main gripe is it's a GTA IV clone. I just liked the overall sheer amount of mini games, the cartoon themed graphics. And all the wonderful customization.
3. Call of Duty: World at War - This is probably the only CoD I truly enjoyed, I mainly liked it for the campaign, the gore, and of course nazi zombies.