Looking for an isp which doesn't need a bt line

Basically i'm fed up of BT and really want to leave them however my area can't get cable so i'm a little limited. Is there any broadband providers out there who don't need a BT line? I thought sky offered one but I heard it was a little unstable.. any ideas?

All services are provided over a BT line (if not cable) but with some providers like TalkTalk they take over the calls and line rental and you pay it to them. They just pay BT OpenReach the wholesale cost of the line.