Finally getting to participate, and doing so without looking at anyone else's list (so I'm sure I'm gonna forget some, and then slap my head and think, "HOW COULD I FORGET THAT COSTUME???").
my #10 pick: Cheetah
I always was a Wonder Woman fan (something you'll find a lot of among young, gay, men), and it was rough that so many of her rogues gallery were 1-offs, or just plain Silly.
Cheetah tended to fall among the "silly" group, and although I did like her original outfit (that big furry TAIL!!!. . not to mention that headgear, even when tweaked to just ears in the 70's for the Debra Domain version), once Perez got ahold of the title, and redesigned Dr. Barbara Minerva as the Cheetah? wow. .it all just clicked.
such a simple design, but within the mythology he created for the re-imagined character, it works so well. and is so beautiful to look at.