With O2 here on the 8Mb plan. There's no traffic shaping and we get it fairly cheap (~£12) due to my dad having a contract on his phone with them. Nothing really outstanding, however.
With Sky, you may wish to read up on the ACS:Law controversy...
The SkyUser forum will have experiences from people who are on Sky, so it's worth checking that out. Be warned, though - I suspect it has its fair share of Sky fanboys/girls...
Check the "Bad ISPs" list on Vuze's wiki, too - it'll let you know of the ISPs that throttle BitTorrent etc.
Yeah I know. Same with Orange.

Thing is we have two Orange contracts in our household. But since we got them the first month we were in the UK and we didn't have a good-enough credit at the time, we had to take them in my uncle's name and then have the money come out of our accounts. In other words we pay the bills but it's not in our names. Which really sucks.
So if we want to get a cheap deal with Orange or O2 we're gonna have to wait until our mobile phone contracts expire in a couple of months and we get new ones in our names.
This REALLY sucks. I think we're gonna have to pay £20 a month. Fuck !