Post "Eve of Destruction" X-Men. X-Men history was finally making sense to me - somewhat, anyways. But anything that happened after this story has left me more confused and less interested in X-Men and the rest of the X-Universe than I've ever been before. I especially hate the killing or reforming all the good X-villains, like Mystique, Juggernaut, The White Queen, and Magneto.
Teenage Tony Stark/Tony revealing his Iron Man ID
And I'm with everyone on the Spider-Clone thing.