Captain America; loyal, kind, and just about as puppy-like as it's gonna get.
Thor; typical asgaardian appetite.
Black Widow; the ass matches and everything!
Hawkeye; Casually corrupted for a while and still badass.
The Hulk; touch his curls (or Louis, for that matter) and HARRY SMASH.
Nick Fury; the movie man that put it all together.
Agent Phil Coulson; the undercover fangirl skills are obvious.