It's just gotta be thor.
he'll get drunk faster
- thor orders asgardian mead
- superman orders milk (louis will throw tantrums if she finds out he's been drinking in a bar)
- ss orders water (cosmic serenity)
- hulk can't seem to figure out how to hold his glass without smashing it
boasting would probably sound like:
superman in a gentlemanly reporter's voice: "Uhm... hey guys, have I ever told you about the time I conquered this multiversal..."
thor cuts in with his booming drunken baritone: "Thou art no match for the might of Thor, man in tights. I have battled frost giants and..."
ss sees hulk looking outcast in the corner and goes, "So hulk, tell me more about yourself"
and hulk goes..." uhm... hulk smash.... errr... smash... hulk... grrr..."
thor will probably have women strapped around his arms by this time. superman can't flirt coz lois will kill him. ss bores the girls away by talking about the cosmic theory... and hulk? well, you guys get the picture.