My exes have not aged well either - one of them has gained what looks like 80-100lbs, and he wasn't skinny to begin with. I, on the other hand, get better looking with age!
But seriously, I used to look for different things. I haven't been in that many relationships. When I was 16, my primary criteria was looks and bad boy-ness, and that relationship lasted five years. Brief relationship break of a few months, during which I had a ton of fun dating and meeting new people in Vancouver, and moved to a new apartment. Then my priority was finding someone fun to hang out with and go do things together. That one lasted six months. Brief dating break of a couple months, during which I had laser eye surgery and learned to ballroom dance. Then my priority was a person I was actually compatible with, and we've been together ever since.
I'm very glad I didn't end up with any of my exes, or other people I considered dating. I don't know where that would have led, but ER probably wouldn't be it.