You're right about me voting for myself; I was an idiot! But as for classifying metal, I could teach you if you want, so let's get started:
- Heavy Metal (especially NWOBHM), leading representatives: Iron Maiden, Saxon, Judas Priest, Motorhead
- Thrash Metal, leading representatives: (early) Metallica, Slayer, Megadeth, Exodus, Testament, Anthrax, Sepultura (even if close to death)
- Death Metal, leading representatives: Cannibal Corpse, Death, Deicide, Morbid Angel
- Black Metal, leading representatives: Mayhem, Marduk, Burzum (on the heavier side), Cradle Of Filth, Dimmu Borgir (for the commercial side)
- Progressive Metal, leading representatives: Dream Theater
- Power Metal (or Epic, leading representatives): (latest) Manowar, Helloween, Stratovarius, Blind Guardian, Gamma Ray
- Nu Metal/Crossover Metal, leading representatives: Korn, Deftones, Slipknot, System of a Down, Soulfly, Ill Nino, Mudvayne
- Industrial Metal, leading representatives: Nine Inch Nails, Ministry
- Doom Metal, leading representatives: Candlemass
I didn’t write this to brag but to show that I know something about metal, and I have at least one album from all the names mentioned (not to mention the discographies of Maiden, Metallica, Slayer, Sepultura, and Priest). Sorry again for the self-assessment!