If You'd Like to Hear it I Can Sing it For You

Alright, this computer's pretty clearly on the way out - the DVD drive is becoming increasingly erratic, and the whole system's going on five years old - if I want to play any recent games with anything resembling decent performance, I'd have to upgrade practically every component anyway...

So I'm planing on going out and getting a new system this weekend. Anyone got any tips on what to look for? I don't think I'll ever understand video card specs...