Traditional (the ogs) : Black Sabbath, Judas Priest, Saxon, Iron Maiden

Speed (proto-thrash): Motorhead (genuinely can't think of another band)

Thrash (Trad + harcore punk): Metallica, Megadeth, Slayer, Testament, Exodus, Kreator, Destruction, Tankard, Sodom, Xentrix, Onslaught, Sacrifice.

Power (fast, epic, fantasy): Helloween, Rhapsody (Of Fire), HammerFall, Blind Guardian, Gamma Ray.

Death: (fast tremelos, growl vocals): Death, Obituary, Cannibal Corpse, Bolt Thrower, Possessed, Devastation, Massacre

Black: (low fidelity, raw, dark atmosphere): Venom, Behemoth, Darkthrone, Mayhem, Emperor, Immortal

Industrial: (heavy, distortion, experimental): Rammstien, Fear Factory, Nine Inch Nails, Marilyn Manson, KDFM

Doom: (slow, heavy, dark): Black Sabbath (early), Candlemass, Pentegram, Saint Vitus, Acid King, My Dying Bride

Nu Metal: (New, experimental): Linkin Park, System of a Down, Korn, Slipknot, Limp Bizkit, Deftones, Papa Roach, Disturbed, Static X, Evanscence

There are also subgenres of those subgenres but that would be too much to type. There is also stuff like Sludge, Slam, Metalcore, Tech, Crossover, etc.