Well I can't listen to any radio with ads on, which cuts the choice down a bit. Have found R4 toooo annoying to listen to as well, apart from the weekly trawl through the Listen Again page which does bring gems.
I'll say it again, though, BBC7 Listen Again is superb. I now have a treasured collection of Goons, Tony Hancock, PG Wodehouse, Just William, Charles Dickens, Conan Doyle, Brontes, Agatha Christie, Steve Coogan, Wilkie Collins, Oscar Wilde,etc etc.
There's some life changing stuff on there - for example last Tuesday's Martyn Wade play about Hermit Lucas, the "celebrated Victorian hermit".
*buys a horse blanket and heads off to live in the kitchen*