UK
Beatles
Stones
Kinks
Who
Small Faces
Animals
Yardbirds
Moody Blues
Led Zep
Sabbath
T.Rex
Slade
Roxy Music
Cockney Rebel
Mott The Hoople
Queen
Fleetwood Mac
Supertramp
Clash
Pistols
Buzzcocks
Jam
Stranglers
Siouxsie & The Banshees
The Specials
Madness
XTC
Joy Division/New Order
The Pretenders
Echo & The Bunnymen
Simple Minds
Eurythmics
Smiths
The Jesus & Mary Chain
Wah (If only for Story Of The Blues)
ELO
The Cult
The Men They Couldn't Hang
Stone Roses
James
Morcheeba
Radiohead
Stereophonics
Suede
Oasis
Muse
Probably a lot more I can't think of right now, and thats not to mention the great solo artists, such as, Bowie, Elton, Stewart, Kate Bush, Ian Dury, etc.
US
Doors
Beach Boys
Velvet Underground
Stooges
The Cars
Steely Dan
Fleetwood Mac
Eagles
New York Dolls
Talking Heads
Blondie
Springsteen/E Street Band
REM
The Pixies
Placebo
Green Day
Guns 'n' Roses
Black Rebel Motorcycle Club
Arcade Fire
The Killers
Again, like the UK, probably a lot more I can't think of right now, not to mention the incredible solo artists from the US, such as, Elvis, Dylan, Stevie Wonder, Sinatra, Prince, Diana Ross, etc.
I think its fair to say both countr
ies have produced an incredible amount of brilliant groups, who have all contributed massively to the music industry