Jerry's is great if you are looking for interesting/weird/strange stuff. i love goin there and looking through everything, but if you are only here a day and are looking specifically for metal/punk stuff, I wouldn't recommend it.

Hit up the Attic for sure. Great selection there. (Plus they still have a few Vicious Blade lp's in stock!)

Preserving Underground out in New Kensington is sorta cool, and specializes in punk/hardcore/metal, but it's a short drive outside of town.

Also take the time to see Pleasant Dreams in Polish Hill.

Government Center is decent, but it's mostly new reissues and things like that. Not really my thing, but you may find a few things there.