I use http://www.coral.co.uk
simple to use covers all sports.Just remember you only gamble what you can afford and enjoy it good luck
Yeah, just signed up to Coral as well. Even better if there's a Coral shop nearby so you can get a connect card and get your winnings from the shop as cash. Their partner, Ladbrokes, also do similar.
Paddy Power and Bet365 I also use. With both of these, you can get a mastercard from them to get instant access to whatever you win.
If you like a combined bet (goalscorers, corners, cards etc) then SkyBet is the way to go - but be prepared to face a longer wait to get your winnings.
Would class those as the top five at the moment.