Have you ever gotten all the achievements/trophies in a game? Is it something you try to do when playing a game? I've only managed to do so for five games: Lego Indiana Jones, Assassin's Creed, Assassin's Creed 2, Harm's Way, and Sonic Generations. I always try to get all of the achievements in a game even the ridiculous ones like "do this x amount of times". The ones I typically don't get are the ones involving online gameplay since I don't have Xbox live. I always get excited when there's a free Gold weekend so I came play previous games and get more achievements.
I've gotten all the achievements on just a few games: Uno, Dash of Destruction, Civilization IV, Prince of Persia (not the DLC ones though, but I 1000/1250ed it), and Assassin's Creed 2. There are a few other games that I could probably 1000 with a few hours of playtime, but I just haven't gotten around to it. I try to get all I can, but the ridiculous fetch quest ones or the ones that are mostly luck-based just annoy the crap out of me. And sometimes I just want to get through a game and don't worry about the achievements - lately, that's been more of the case.
Assassin's Creed, Assassin's Creed II, Portal: Still Alive, Portal 2, & Plants vs Zombies. That's it for games with obvious achievements (XBL or Steam), though some games, like the recent Kingdom Hearts games, have achievements/trophies in the menu and aside from Re:Coded, I've gotten all of those. :/ I tend to only go for achievements if it looks like fun or if it doesn't seem like it'll be that much more work than playing what I want of the game. So for example, I wanted to unlock everything in the first two Assassin's Creed games anyway so I ended up 1000/1000ing them. But Brotherhood? I got all the single player achievements and got maybe one or two multiplayer ones before setting it aside. The other achievements just didn't interest me at all.