I've had a hard time finding a reliable UK source for straight ahead rock music. I'm a fan of Foo Fighters, System of a Down, Green Day, Nirvana, Alice In Chains, Oasis, and a bunch of smaller bands in the same vein.
In the US, I used to be able to listen to Squizz and Ethel on XM Satellite Radio to hear new bands, and since it played without commercials, I could leave it on in the background all day. When something I liked came on I could see what it was immediately. This was awesome.
Over here in the UK, I like a lot of the stuff that's played on Kerrang and to a lesser extent Scuzz, but Kerrang and Scuzz repeat the same stuff over and over again throughout the day, and only rarely play new music; they stick with rock hits rather than emerging artists. The only new band I've found since coming over here 13 months ago is Reuben.
How this relates to the UK/US music scene is it seems to me that rock bands with grungy looking people playing distorted guitars and shouting are not as popular in the UK as rock bands with good looking people dressed well (if ironically), playing in a quirky style and singing prettily.