Here is a great cover that I almost thought was done by Gil Kane. It features a familiar theme, the hero bursting out of the comics page.
The jungle lord Ka-Zar and his best buddy Zabu are jumping out of the page directly at the reader, in Astonishing Tales #16, circa 1972.
I found the original art to this on Heritage. It looks to me like Jim Starlin penciled this cover and John Romita inked it. Ka-Zar really looks like he is in a typical Starlin pose, but the inking is undeniably Romita's crisp line. Gil Kane's presence is still here, since his artwork is on the page in the background. Nuff Said!