I do, they give me a good sense of progression and a good motivation to keep playing the game. I only care abou them for the games I really love though. I think they're a good idea.
Plus, there was that awesome moment in Spec Ops: The Line (I don't think I need spoilers for this...) where you come across a corpse hanging from the ceiling, blackened and mutilated, and as you walk towards it and finally reach it, you hear the ding of a trophy popping. A trophy called "The Horror". That bit was so wonderfully hollow, it really made me question my moties. I'm doing horrible things to people, and for what? A meaningless virtual achievement? Is this what gaming has become? That was an awesome moment, in my eyes.