I like the cover of X-men #1 vol.2 from Oct 1, 1991. That cover was not only cool but marked a historically moment in the history of the X-men, the very first time they had two adult teams of X-men living at the Manison.  That cover was a pulled cover that contain all the X-men from both teams, it was awesome. It was this issue that turn me onto to drawing comic book heroes..