When I'm not playing MMOs, I'm usually found on a console. Of all the numerous machines and debugs I own, my Xbox 360 is my favourite. It's the one console I saved hard to buy and waited the longest for. While I think it has some of the best games, it also has Achievements. It's really sad, I know, but I love that little ding and onscreen notification which lets me know I've achieved something in-game. From finding a secret area or finishing a game, there's something about that noise which is rewarding.
But now achievements have started popping up in MMOs (in the form of actual achievements or special titles for completion of certain quests) and it's so much fun. What is it about being rewarded? Are we just rats being given cheese for completing a maze or do achievements help keep interest in a particularly long quest chain or boring instance we'd never otherwise complete?