I'm with BE
https://www.bethere.co.uk/ and i'm impressed, you do need a bt line and it is 125 quid if you've never had one at the property before, if there has previously been a phone line there then there shouldnt be any problems reconnecting it. If you do need to pay the 125 quid i'm sure sky did a deal where if you signed up with them they'll refund the install charge (125 quid) you'd have to call them to check that though as i'm not 100% on that.
If you have an O2 mobile have a look at here
http://broadband.o2.co.uk/home/index...o2%20broadband as you get a discount if you're a mobile customer too, BE and O2 are part of the same family and i've heard nothing bad about either, yet
