I'd like to agree with the GRAW Achivements heartily. Screw them, I'm just going for the mission ones then never touching the game again, I'm not much for it.
Brass Balls in Bioshock isn't hard actually. All you do is go into options, make sure the "Disable Vita-Chambers" option says ON. Then just use that save feature like it's going out of style. Save whenever you kill a group of splicers, get a Little Sister, pick up a quest item, heal all the way, upgrade a weapon. Save, save, save.
The research ones pissed me off though. Not too much however, Bioshock is an excellent game, and I don't regret pumping so much time into it.
The "Flawless (insert insturment here)" Achievements in Rock Band are pretty insane too. It's not the difficulty, it's the mindset. You're so scared that you might screw up, that you can and will screw up. I've got the guitar and bass ones. You'd think the singing one would be easy for me, considering I sing in a real band. Ah, no.
For some reason, the "Kill five guys with an energy ball" one in Half-Life 2 is eluding me. I'll get it sooner or later.
I'm an Achievement whore, what can I say?