I have had past experiances with http://www.plugpayplay.com and http://nitrous-networks.co.uk the later of which was frankly bloody awfull. I had a small amount of time with Daemon server hosting which as far as I could see was ok. Any advice and recomendations would be nice and past experiances will be duley noted.
Gmod Server (forgot to say)
Price is flexible, no more than £60-70, fastDL etc needed. More good stuff the better!