Kermode & Mayo's film reviews
Collings & Herrin
Adam & Joe
As It Occurs To Me (Richard Herring topical stand-up show)
In Our Time
This American Life (really well done and interesting documentary type stuff)
The News Quiz (I delete The Now Show & IGTWTCITN immediately when they come on)
Vintage Tooncast (classic cartoons that are now out of copyright so free)
David Mitchell's Soapbox (not current but still downloadable)
I also like the Smithsonian Folkways shows on iTunes U - not strictly podcasts but more or less.
Never heard of The Bike Show - can see I'll have to investigate it. And some of those Radio 3 ones sound good. And I really like the sound of Answer Me This.
I've been trying the Precious Little podcast recently but I'm not really smitten - it's a poor man's Collings & Herrin. Likewise, I tried Phill Jupitus & Phil Wilding's Perfect Ten but it seems to be just lots of swearing for swearing's sake.
d.