I only really like an actual costume when it makes sense. Spiderman and Batman for example wear one to hide their identity. Captain America wears one because he's meant to be a symbol to the people. If it's just being worn though for the sake of "well they're a superhero so they have to have one" then I don't really care how good it looks because the outfit is just filling a stereotype and probably doesn't have an explanation that feels natural for the character to be wearing it.
However I genuinely think no superhero costume will ever be as bad as this:
I'll never understand why anyone would look at any superhero costume and think "You know what this needs? Nipples".