After looking at hundreds of comic book covers, it becomes quickly apparent that not every cover is 100% original. Whether done intentionally or even underhandedly, there's something about uncovering these "swipes" that adds a new element of fun to reading and collecting comics. 1991's X-Men #1 is the best-selling comic of all time, reaching 8 million in sales. Part of those figures are due to the variant covers (5 of 'em!) that were released. The other part was due to the incredible popularity of Jim Lee's art, at the time. Since it's been so well-embedded in the social consciousness of comic fans, all of the variants have become targets for cover swipes over the year.
X-Men vol. II
October 1991
Jim Lee
 Lethargic Comics, Weakly #4
September 1991
Greg Hyland
Marvel Zombies: Dead Days
July 2007
Arthur Suydam
On Ebay: X-Men | Lethargic | Marvel Zombies | Jim Lee | Greg Hyland | Arthur Suydam