I'm going through my collection, doing a full audit to see what I really want to hold on to. I'm planning on selling anything that I don't play, have no desire to finish, or just got for the cheap/oddball factor. I've finally gotten to the point where I don't want shelves full of dusty cart-only games, and I'd rather focus on the stuff that I'm either really into or actually have the time to play.
My problem is that I'm not exactly sure what's good to keep around and what's not, from a collector's perspective. Stuff like old sports games are a no-brainer, but what about the random platformers, and "average" games? What criteria do you use to separate the wheat from the chaff?