Spider-Man and the X-Men. The comic book series.
Incredibly underrated and forgotten book. But one that has everything I like. It has worldbuilding, two sides of the MU (Spider-Man and X-Men) interacting in meaningful and interesting ways and a fun, light-heart tone that made everything all the more enjoyable. Sadly the Match-Up fell into obscurity because he was teaching nobodies rather than any fan favorite. But still, I really loved it. From the mere concept of Spider-Man teaching kids (mutant kids at that) to them looking up to Spider-Man and fighting alongside him.
Honestly Spider-Man as a professor of the Xavier (Or Jean Grey's) School for mutants sounds like a rather cozy endgame for him after he retires.