From personal experience, and in no particular order:

* Rivelin Folk Club, Rivelin Valley, Sheffield
* Conwy Folk Club
* Ryhl Folk Club
* The "Blah Bar" events organised by Tony Heald in Barnsley

I would also guess Gainsborough is worth a visit, from what I hear from Sooz and others.

And if you fancy some decent music in a pub setting try:

* The Junction, Otley
* The Neptune Bar, Brighton

Both noisy but fun!

And finally:

* The Greys, Brighton

All the best
John Robinson
http://www.JulieEllison.co.uk