Avengers - they have a god (Thor), the most powerful (strength) fictional character in natural comicdom (Hulk), a human with comparable strength and stamina to mutants (cpt america), and some other fools with gadgets or sharpshooting ability (Iron man and Hawkeye)

The X-Men are a ragtag clan of misfits with special powers. Thor could single handedly mop the floor with all of them.

Thor really is overpowered. IIRC he should be stronger than Superman.