Comic-book auctions have become quite a lucrative market in recent years, and the king of this particular hill is Dallas' Heritage Comics Auctions. For example: Last year, when Nicolas Cage decided to sell off his entire comic-book collection--which contained such prize books as Action Comics No. 1 (the first appearance of Superman) and All-Star Comics No. 3 (the debut of the Justice Society of America, the first superhero team)--he went with Heritage. Spider-Man/X-Men/Fantastic Four co-creator Stan Lee also tapped the auction house when he wanted to sell off a sizable chunk of his (obviously) extensive assortment of books. Though Heritage still deals primarily in rare coins, the comic trade made the company more than $10 million since it began dealing in funny books in 2001--and that was before they helped Cage sell his collection. If you've got a big wallet rubbing up against a set of Incredible Hulk Underoos, look no further. Oh, and the second-best place? Mark Cuban's house.