Exodus, Nuclear Assault, In Flames, Blind Guardian, Symphony X, White Zombie, Bullet For My Valentine (owes more to punk than metal, but still), Machine Head, Behemoth, Celtic Frost, Skindred, Rob Zombie, Death Angel, Within Temptation, Dream Theater, Metal Church, Razor, Exhorder, Monster Magnet, Static-X, Kat, Suicidal Tendencies, Melvins, Black Label Society, Iron Maiden, Children Of Bodom, Dark Angel, Coroner, Type O Negative, Dope, Ministry, At The Gates, Holy Moses. Black Sabbath, Forbidden, Sons Of Otis, Ozzy Osbourne, Whiplash, Venom, Judas Priest, Five Finger Death Punch, Sadus, Voivod, Annihilator, Vio-Lence, Meshuggah, Kreator, Destruction, Shadows Fall, Nightwish, Danzig, Oomph!, Nine Inch Nails, Mushroomhead, Testament, Sepultura, Sodom, Killswitch Engage, Overkill, Morbid Saint, Onslaught, Lordi, Deströyer 666, Motörhead, Deathrow, Artillery, Antrax, Megadeth, All That Remains, Rammstein (a little bit here and there), Heaven & Hell, DevilDriver, Apocalyptica, Mötley Crüe, Flotsam & Jetsam, Pantera, Metallica, Atreyu, Faith No More, Tool (eh, prog rock more than metal but whatever), Slayer, Mastodon, Fear Factory.
+ Some pre-metal stuff like AC/DC, Zeppelin, Deep Purple etc that could be considered metal but is more hard rock.
atm really into thrash, at least 50 bands that I want to check out. Also looking into some doom.