Nu-Metal: Korn, Disturbed, Slipknot and System of a Down
British Invasion: The Beatles, The Rolling Stones, The Who, and The Kinks
Grunge: Nirvana,Pearl Jam, Soundgarden, Alice in Chains
Thrash: Metallica, Megadeth, Anthrax, and either Slayer or Testement, depending on who you ask.
You skipped "classic metal"
Black Sabbath
Judas Priest
Iron Maiden
Motorhead
Missing in action:
Enter Sandman
Battery
Paranoid
Let There Be Rock
Anyway You Want It
Give it Away
Spoonman
Bring them home HMX!
What about the big 3 of shoegazer?
My Bloody Valentine
Ride
Slowdive
It's not a big 4 but the combined awesomeness of the 3 together makes the equivalent of a fourth band.
Would you pay for music by Beck?
Maybe.
What if you heard he owned a plane made of gold?
Sure.
Good, because he needs the money.
Big 3 of Teutonic Thrash
Kreator
Sodom
Destruction
Grunge wins. The other "Big Fours" have at least one mediocre-to-crappy band that brings it down below the awesomness that is Grunge. Nu-Metal has three, which is probably why it doesn't have any votes.
I will not remove this until Badmotorfinger is offered as full-album DLC.
British Invasion is first because all the bands are great.
Grunge is second because I love Pearl Jam, Nirvana and Soundgarden, but I'm kinda indifferent to most Alice in Chains.
Thrash is third because Megadeth and Testament are great, but I think Metallica's merely decent and the other two aren't my bag at all.
Nu-Metal is a distant fourth. System of a Down is OK and I can tolerate Disturbed, but I despise the other two.
"You're an angel witch, yoooou're an angel witch."
-hit single Angel Witch by the band Angel Witch, from the album Angel Witch.
Well, everyone, prepare to have your guts kicked out by folk singers...