Well, I level up a lot of skills, which gives me a lot of xp.

I have Alteration, Restoration, Heavy Armor, Blocking, Smithing, Enchanting, Sneaking, Lockpicking, Pickpocketing, and Illusion all above 50 and those are just the ones I can remember off-hoof.

Also, Blocking is maxed and Sneaking, Enchanting, Smithing, and Heavy Armor are all pretty far up there.