Oh god, I'm actually gonna say it: I LIKED Modern Warfare 2. That's right, I liked it. And no, I'm not a IW fanboy. I honestly think the haters were overdosing on their haterade when this game came out, it is not NEARLY as bad as they claim it is. Are there problems with it? Hell yes. The multiplayer can be pretty unbalanced, the story feels more like a Micheal Bay movie than a Call of Duty game, and it's both incredibly realistic and insanely action movie unrealistic at the same time, which kind of clash with each other. But you know what? I actually ENJOYED the action movie moments. And I also kind of like finding ways to defeat some douchebag in TDM because he's spamming that Grenade Launcher/One Man Army combo. There really is something really fun about doing stuff like that, and I have no problem with it. It IS like a Micheal Bay movie, but hey, Micheal Bay movies can be fun sometimes
Another one is The Halo series. I really can't understand what the haters see in it that makes it so terrible. It IS kind of generic, but I think this is more of a "Seinfeld is Unfunny" effect than an actual criticism