Wildfire was arguably a pretty minor hero, and I only knew him from one Legion of the Superheroes story. (From around #200.) To this day, I know very little about him. In fact, when I started writing this post, I had to look him up because I couldn't even remember his name. But dang, did his costume rock!
I think I was largely attracted here to the mask. I suspect that the complete anonimity of the character was intriguing -- he could be anyone. Not unlike Spider-Man. He was totally covered from head to toe, PLUS his mask just reflected back whoever he was looking at. That just reeked of coolness.
The chest emblem was a little weak, I thought/think, but it's not terribly distracting since it's yellow on a field of orange.
One of these days, I should look him up and see if I can dig up some good Wildfire stories. That was too cool of a costume to let languish.