I never had any "Major" achievements that got me all excited and all but theirs a few that im happy about but not like shaking happy. Its more like "yay did it >.>"
Left 4 Dead: Zombie Genocide. (kill 53k zombies)
Super Smash Brothers Brawl: Cruel Brawl (Killed 11 people in it)
Soldat (pc shooter game): Was in 2nd place in kills...
I cant remember which Guitar Hero it was now.. But for some time i was 35th best in the world (According to PS3 Leaderboards(Not including Xbox)) at the song Re-Education Through Labor xP
I friggin loved GH, but haven't played it much lately.