Lastly, one of my favorite all-time genderswapped cosplays, the whole damn Justice League. This group first made an appearance at Wondercon 2011 and have continued to grow their ranks since then, adding a Hunter, Black Canary, Martian Maneater, Power Boy, and more.

The Mary Sue has a good write up on The Gender Bent Justice League, with more pictures and links to read on. They've been adding on more members with each Con they attend, and are trying to use their notoriety to make a point about female characters in comics. You'll notice that everyone's costumes are as scanty or as modest as the original character's, regardless of gender, and that's their point. If gender in superhero storytelling is your bag, I encourage you to read more.