I never got into any DC characters. Galactus wasn't much fun because there wasn't really anything you could do about him--they'd all just mill around and panic until something came along and saved their butts.
Omega Red, however, was an entertaining villain. I didn't really like Wolverine, but a lot of the characters around him--Omega Red, Sabretooth, Maverick, all the Japanese characters--were pretty cool.
Anyone remember the name of the dude with adamantium skin? Not Colossus, but one of Wolverine's villains. I think he broke Wolvie's claws once.