Slayer, Queensrÿche, Judas Priest, Pantera, Megadeth, Sepultura, Clutch, Black Sabbath, Metallica, Anthrax, Danzig, Fear Factory, Machine Head, Iron Maiden, and TOOL.
I could go on but meh. These are all fairly well-known and popular bands. Some of them have already been on GH games. They could easily make a metal GH.