X-Men: The Complete Onslaught Epic, Book 2 (v. 2)
Professor Xavier has now been subsumed by Apocalypse, mayhem and chaos has ensued and it's up to the Marvel Superheroes to try to fight it. Several of the stories are quite interesting in the dicotomy between an ordinary human life and the responsibilities of having power and needing to use it to better other people's lives and keep them alive.
