You could really do something fantastic mixing punk and metal. I'm doing that right now. And my band consists of people from different "scenes". We have a lesbian semi-crust punk that plays in punk bands but loves Metallica on guitar. Our other guitar player is a skin that came up playing pop-punk (think Lifetime, Dillinger Four). Our drummer (also a skin) plays drums in a punk band and our x-over band and loves more current HC like Backtrack, Terror, etc. Our vocalist is a farmer and sorta a skin and loves everything from Merle Haggard to Agnostic Front. I'm sorta a skin and my favorite bands are Sepultura and Gorilla Biscuits.
The thrashier sound mixing heavy metal and punk or hardcore is super popular right now with current "new school" bands like Power Trip, Bitter End, Take Offense, and Will to Die mixing influences of stuff like Anthrax, Slayer, and Sepultura with a more modern hardcore sound and bands like Cro-Mags, Suicidal Tendencies still touring and playing shows.
Not to mention that it's fun.