The choice you made is cool. Nobody cares, so you don't have to worry about that. Hell, some of my friends are of your type, too, but I don't make a big deal about it. It's their (and your) lifestyle choice, not mine.
PM2 > DOAU if you're into single player
DOAU > PM2 if you're into muliplayer
PM2 will last you between 30 and 45 hours. The more sidequests, the longer your playtime. The story is charming, witty, and keeps a smile on your face long after you finish your gaming session.
I haven't picked up DOAU yet. I'll do that after Halo 2, Mario Tennis, Metroid Prime 2, Metal Gear Solid 3, Nintendoods w/ Mario 64DS and Zelda: Minish Cap.