I have wireless telewest broadband (about 512kb) - 'tis ok even on my ancient laptop and does the job. Haven't had a problem with it yet, and together with the Telewest 3 for £30 package (+ telephone line rental and a basicish cable tv package) is ok for me. Think it is still unlimted use of downloads.
The old man-in-law has BT Broadband - a Voyager 105 modem - 2.2mb - very quick, easy to use, and was most impressed with it. Does need a BT phone landline though. Not sure how much he pays monthly for it though - or if there is a limit on the downloads.