Hmmm.
Most difficult, craziest and hardest would be DOAX2's clothing quest achievements. Expecially when you obtain all of them. I/my friend spent 5+ hours on the game and got 5 achievement points! Rather useless for a crappy game. Achievements should of focused on obtaining certain times and point values on the various games.
Most satisfying achievements are many, as I always enjoy each one I get. Getting 1250/1250 of Oblivion was alot of fun. Infact, every RPG achievement I've got was very satisfying, as RPG achievements have usually been great. I'm still working on Blue Dragon (85/1000) and Eternal Sonata (140/1000), but even though they are difficult, they aren't as abstract and stupid as other games.
Least satisfying are the achievements from most American football games (sans NFL Blitz). Usually in the 1st game, you can unlock 5-10 achievements. Who cares if you make a 20 yard pass or score a touchdown!?
Back from the dead, I'm afraid.
