DoW Lowen said:
I think in Batman "Party Pooper" achievement was a hell of a surprise. I just happened to beat the room full of guys up for the fun of it, and after slamming the last guys head into the ground the sound came up. Best moment of the game for me.
Frustratingly for me, that was the only achievement I missed in Batman apart from the hard difficulty one so I had to do it in hard mode which made it much more interesting.
Hoard the Horde in GoW2. I did it solo and it took me ages to do. When I got the last guy I was so exhausted yet exhilarated by the experience and the little blip boop sound of the achievement was like the music of the gods to my ears. It was also the last GoW2 achievement I had to do, apart from the live ones which I can't do because I don't have live. I could do seriously 2.0 I guess but I'm not that desperate for points.
Honourable mention to Survive the Professor in Bourne Conspiracy. It was on the hardest difficulty and I'd heard it was an immensely frustrating bit to beat and the hardest portion of the game. I managed to beat him with a mere half second to go on my first try and the build up before hand, the intense fight and my successful completion on the first try made it a pretty special achievement at the time.