I've never played a video game I don't like. Usually, if I take the time to get a game, I will enjoy it.
However, I must mention Rainbow Six: Lockdown. Seriously, what the freaking HELL?! Coming off of playing Rainbow Six: Raven Shield - a fine game, I might add - then comes Lockdown. Seriously, what happened? They took a perfectly fine tactical shooter with all the necessary bits, and turned it into a generic action game. Planning? Gone. Realism? Gone. Hell, actual weapon names and good graphics? The usual standard of a Tom Clancy game, hell, any sort of tactical shooter?!
...
Oh, woe! Rainbow Six, how far have you guys fallen?
Rainbow Six Vegas was closer to the actual tactical shooter style, at least. However, while I'm at it, it too, deserves to be mentioned here. Of course, Vegas is a good game. It's got the cover system, it's got all the fancy graphics and nifty gameplay bits. It's a good game overall...so long as you're playing on the Xbox 360.
Otherwise, if you're like me and if you're trying to play it on your PC...oh, ye Gods! Howl! Howl! Howl!
Don't even think about it unless you've got a Shader Model 3.0 video card. No, seriously. The game doesn't even RUN unless you've got that specific part. Hell, I've seen a good gaming laptop - fitted with a GeForce 7800, 2.8 Ghz Pentium IV, gig of RAM, etc - get absolutely destroyed by this game. Funny part about that? That was the freaking menu.
Of course, the Unreal 3 engine is insane on its own, so it shouldn't surprise me all too much that Rainbow Six Vegas practically kills almost every machine out there currently. I suppose it's a sign of the coming times - we all must upgrade, lest we be without the next generation's best games.
...either that, or buy an Xbox.