All the marvel characters vs all the dc characters...   stance: spidey, x men and the hulk might makes right!:
As powerful as superman is- he does have a noted vulnerability to psionic powers, so professor X (or phoenix, or apocalypse) would be able to control/trap/destroy him.
And Batman has no powers- just gadgets- Magneto could make short work of him.
And the flash? So he runs. Wow. Oh yeah, professor X could take him down too. In fact- professor X could probably take them all out by himself without all the other god like marvel characters.