I was inspired to ask this question after rereading my own personal choice, Avengers Unplugged 3. Black Widow and Crystal get dressed up in miniskirts and have a "girls' night out" at a male strip club called, uh, "Bimboyz." Coincidentally enough, it's hero night at the club, and at one point Crystal attracts the attention of a male stripper dressed as Quicksilver.
As a fantastic article on the Avengers Assemble website points out, the comic hits its nadir when Black Widow says "You go, girl!" to Crystal.
Avengers Unplugged as a whole was truly, horribly, abominably bad, and #3 get my vote for the worst Avengers issue ever.
It's a toss-up between Avengers:The Crossing and the Timeslide one-shots. The whole "Iron Man was evil the whole time" and "Teen Tony" thing left a bad taste in my mouth.
The Image-inspired new costumes didn't help matters either. *gah*