I've collected a bunch of supers HeroClix over the last month, since I've been reading a bunch of supers rpg's. Talk about perfect for Champions, Villains and Vigilantes, and any other minis-required superhero rpg. If you play either game, you really should take the time to get at least a small collection of HeroClix.
I have no intention of ever playing the HeroClix minis game, and in fact, don't even have a ruleset to learn it.
I spent around $100 on eBay and Noble Knight, and have almost every superhero I could want (some are ridiculously rare and expensive, though, like a yellow Sinestro). All these supers minis, and not one pot of paint required. I love it!
I do think it's kind of funny that DC Adventures does not require minis, and yet it has a mini for almost any DC character you can think of readily available. I suspect that the upcoming Marvel game, which uses Cortex, will also not require minis in any fashion.