I don't know that I fully grasp the appeal of premium skins in Minecraft: Xbox 360 Edition, but I was never one to buy crap for my Avatar, either, so I'm clearly not the intended audience. If I were, however, these characters from the upcoming Avengers Skin Pack might just do the trick.
I mean, look at that -- they made the Red Skull adorable. Some of the confirmed characters include Captain America, Iron Man, Hulk, Thor, Nick Fury, Black Widow, Hawkeye, Loki, Wasp, Falcon, Vision, Maria Hill, and Agent Coulson (of course). No date has been given yet other than "coming soon." Seems like something they'd want to get out by the end of the year, however.