Black Widow wears a slightly revealing dress earlier on in the film

nothing else

some WWII-related action at the beginning

the avengers fight and eventually kill an alien in a non-graphic matter.

The Hulk takes on all the avengers at the end of the film and starts to beat up Captain America until his face is pretty bloody

"Damn" "Hell"

a few characters light cigarettes here and there

The Black Widow meets Tony Stark at a very fancy bar where they order Martini's

none.