Virgin Media... also, AOL did tap into the NTL Telewest infastructure for a few years, not sure if they still do though?
Madasafish line-rental and o2 Broadband is only costing me like approx £16 a month so it aint exactly breaking the bank lol.
Virgin's basic package is £15 per month, if you want it without a phoneline, so not much difference in all honesty. The difference between Virgin and o2, is obviously customer services, but more importantly, o2's definition of "unlimited" is actually basically unlimited, and Virgin's is quite different from what you would call unlimited. Not to mention hurrendous traffic shaping, no net neutrality, service throttling and serious backbone capacity problems at peak times.
There is of course satellite broadband, but for a service without a phoneline to upload, your talking mega-bucks and the lag is awful on it lol.