9. X-Men #1 Is The Best-Selling Comic Book Of All-Time
The '90s were a weird time for comic books, but the industry was really booming. The X-Men in particular were a very hot commodity at the time, and even all these years later, Jim Lee's X-Men #1 (published in 1991) remains the highest selling comic ever. It even holds a Guinness World Record, and the chances of that ever being beaten seem unlikely. After all, the most recent addition to the top 10 selling comics is Amazing Spider-Man #1 in 2014, and that sold 533,000 copies in comparison to X-Men #1's 7 million. The best part about such high sales is that it's surprisingly easy to find a copy on eBay for a reasonable price.