I was wondering about western-style superheroes in anime myself. My guess is that with the success of Spider-Man and X-Men as films, we will see some of that influence in new anime.
Anyway, I agree with the first Project A-Ko, especially for the joke at the end. And don't forget Battle Of The Planets (aka, G-Force).
Also, if you have G4TV, check out their late night anime show Anime Unleashed. They are currently running a series called Gad Guard. While the main charaters don't have superpowers, they do have a western superhero feel to them. The characters hang on to these 15 or 20 foot tall robots called "Gads" to fight. However, they wear homemade costumes (no transforming in a flash of light), and go on nightly patrols to fight crime.
Since it's on TV, it won't cost you anything to take a look at it.
Maybe Cutie (Cutey) Honey? She an android with the power to assume the form and powers of different occupations. Sounds weird, but if she, say, needed to fly a helicopter, she would turn into a pilot and know how to fly it. There was an episode where she turned into a pro-wrestler to win a fight.
There's a live-action movie which I really want to see. I'm not sure about its status concerning a US release.
Oh, and Giant Robo has a bunch of superpowered characters. I thought they were more interesting than the robots.
Other than that, I don't know. I suppose you could look at some of the fighting game animes out there like Fatal Fury.
