ok I think that Muse comment might rub some people the wrong way. my apologies.
here are all my favourites:
Ash, Blur, the Clash, Manic Street Preachers, Oasis, New Order, Joy Division, the Smiths, Stone Roses, Happy Mondays, Paul Weller/The Jam, Elastica, Suede, Richard Ashcroft/The Verve, Nick Drake, Duran Duran, Ryan Adams, Doves, Pet Shop Boys, Idlewild, the Pogues (thanks to IWB), Smashing Pumpkins, Radiohead, Juniper/Bell X1/Damien Rice, Mull Historical Society, Neil Young, Super Furry Animals, Gorky's Zygotic Mynci, the Decemberists, Saint Etienne, REM, Stiff Little Fingers, Pulp, the Ramones, Coldplay, Split Enz/Crowded House/Neil Finn, Francoise Hardy, Jacques Dutronc, the Streets, the Darkness, Placebo, Belle & Sebastian, the Charlatans, Elvis Costello, Nick Lowe, Foo Fighters, Neutral Milk Hotel, Dropkick Murphys, Flogging Molly, Neko Case, the New Pornographers, Paul Westerberg/The Replacements, the Sleepy Jackson, Sophie-Ellis Bextor/theaudience
, Tom McRae, Sleater-Kinney, and the Cure. etc.