I liked Marvel's New Universe line when it came out too. It may've been a little better, and lasted longer, if they maybe focused on a few less books. They weren't all crap. I liked Starbrand, and how it came over to Nova, or whoever.
Another one I liked was Marvel's 2099 books, especially Ghost Rider. I've since gotten rid of most of my collection, including that, and wouldn't mind seeing that in a TPB.
The variant covers were already mentioned, but any 1st ish that had some huge balloon stating it was the 1st ish and a collectors item.