I had picked up Ultimate Spider-Man #1-6 & Ultimate X-Men #1 way back. Are these worth anything? I couldn't find them on ebay.

If they're first-prints and they're in pristine or near-pristine condition, then they're worth a few hundred dollars all told, according to this website. Personally, I have my doubts that anybody would buy them for that much given the fact that they are readily in print in TPB form, but who knows.

Way back? They're not that old.