For some reason I care quite a bit about achievements on the 360. But I don't care at all about trophies on PS3.
Does that make me an Xbot?
I'm more or less the same. Though I wouldn't say I don't care at all about trophies, I definitely prefer achievements.
I may have something to do with the me-too aspect of it, or the fact that achievements are in every 360 game but only some PS3 games have trophies. It may have to do with the structure, in that every 360 game has 1000 points, XBLA games have 250 and expansions can add, IIRC, 100 more points. Trophies seem willy-nilly. I think it's more reward and response, though, in a Pavlovian sense. I like the icon that pops up for achievements and the sound that goes with it. It seems easy to miss getting a trophy.
+1 Achievements have been there from the start, so it's hard to be as excited about trophies. As they improve trophy support online, I'm sure it will get better, as part of what is fun about achievements is the ability to easily compare yourself to other people and play with things like mygamercard.
I have read that there are actually a total number of trophy points that is identical game to game, but it is not visible like it is with achievements. This is how the "trophy level" works. It's like XP in an RPG. You can get a max number of trophy points in each game towards your trophy level. The higher your level gets, the more points you need to reach the next level.