The alarming image of Wolverine crucified against an X-shaped crucifix met X-Men fans on the cover of Uncanny X-Men #251 in 1989.
The story contained within the issue was even more horrifying, as it was revealed that this crucifixion was the result of an encounter with a dastardly gang of cyborgs called the Reavers. Throughout the issue, he is tormented by his captor, Donald Pierce, and his disturbed state of mind leads to hallucinations throughout the issue.
While this is far from Wolverine's most painful experience (this is the man who had his heart torn out and his skeleton infused with metal), the image of the clawed mutant crucified is a gruesome one that has likely shocked and horrified many fans. This induction of shock and horror from the fans makes this one of the most emotional Wolverine moments ever published.