I should begin by saying that, when you think about it, many of our best loved super heroes have some of the worst costumes. For example, Superman's costume isn't that great. We are so used to it and it is so iconic that we don't think about how lame looking it really is. Also, a lot of comic book stars don't really have much of a costume at all - Thing runs around in his underwear and Hulk has purple dungarees. So, these don't count. I'm looking for bad, painfully bad costumes.
After grazing around various sites, here's a few I found that that stand out as particularly bad.
Vartox was a rip off of Zardoz, the character played by Sean Connery in a movie by the same name. As if the costume wasn't bad enough, the cover just had to feature a crotch shot.
Speaking of crotch popping, idiotic looking costumes, B'wana Beast may be the absolute worst with an insane looking Mexican wrestler mask and a loin cloth.
Next up is Timber Wolf. Dig those zebra striped epaulets! This picture and more found here.
Retrocrush has a list of the worst superhero costumes found here. Topping the list is Daredevil sporting "a costume only a blind superhero would pick out". Fortunately, this outfit only lasted eleven issues.
Kraven the Hunter looked like he could have fit right in with the Village People.
At least Kraven didn't have a crotch laser cannon...
Of course, that one was intentionally funny, so I guess it shouldn't count.
But why should the guys bear all the fashion criticism? There's been plenty of bad costumes worn by superheroines as well. Take for example Boom Boom, formerly known as Meltdown from The New Mutants and X-Factor. Good Lord, that's bad!
But that's nothing compared to the next superheroine, who takes the prize for the worst all around appearance. Close your eyes if you're prone to night terrors. It's bad, real bad. I give you.... She-Thing!
Eegad, this superheroine is an abomination! She's Thing with boobs and it's frankly hard to look at. I don't get why the female version of the Hulk (She Hulk) is hot, yet the female version of Thing looks like a gym teacher with bad skin. I apologize for exposing you to this. Just keep repeating to yourself: Power Girl, Power Girl, Power Girl.... and it will all be okay.