In my opinion is that avengers would beacause not only do they have the will power, but they have also found a way to work together.
Two quotes that make me think the avengers would win,

"even if we loose the world we will avenge it."

"ya, well we have a hulk."

Not only that hulk is getting better at controling his powers, hawk eye could shoot a couple explosive arrows and boom.

Bad thing about wolverin is that he has a bad attitude and doesnt like to work together, avengers learend how.

Those are my thoughts.

AVENGERS!