@tchallaisopness: I think Hawkeye can kill him using his trick arrows, without powers he is just as strong as Hank Pym would be in his size. But deepends how tall Galactus actually is because his size varies, sometimes he looks bigger, and other times he looks smaller.
No prep-time implies that they won't know anything about they opponents therefore they won't have a special item that would help them in the fight.
Standard equipment implies that they would only have the equipment they have normally, like Batman he would only have his utility belt, batarangs and suit.
Well I think I define powers as anything above human beings, for example Superman won't have his Kryptonian physiology, but he would be as strong as a human of his size, and with similar muscle mass, which I guess is easy with Superman because at least he has feats with human like physiology. Just make your way with your arguments.
Oh, and in the first fight it would be only fists.
@lejon: Actually as I said, I don't believe in anything, I read about science and try to understand it, I judge and trust the work of the scientists, but I never believe on it, believing on something is just swallow something without having chewed first.
Your team must win the previous stage to move to the next one.
To defeat the Avengers all your characters must cross all the stages, if one of them loses in one stage all the team does.
You must explain why your team would win on each stage and at least 3 viners must agree with you.
Each stage has different rules.
You can't pick the same characters that I used on this list.
Morals off for the Avengers and your characters.
Stage 1: The Captain America and the Black Widow
The fight takes place in an abandoned city.
On this fight your team have lost all his powers, they just have all the skills they have developed during their lives, and they must defeat Steve and Natasha in a H2H combat. Steve does have his shield; Natasha does not have any of her equipment.
Stage 2: Hawkeyes.
Your team start on a forest, in the middle of the forest there would be a huge circle lacking of trees and vegetation, with a diameter of a mile and a tower in the middle of that circle, Clint Barton (Utimate, 1610 Universe) and Kate Bishop would be inside and they would have a perfect sight from all the circle, but in the forest your team can hide.
On this fight your team has lost all his powers, your team have not prep-time and their standard equipment. Clint and Kate have all their trick arrows and 40 regular arrows.
Stage 3: Thor and the Hulk.
The fight takes place in a desert; your team has all their powers, not prep-time and they have their standard equipment.