I've been a member of Yougov for quite a few years now, I think its quite good. Usually get about 50p or £1 per survey, and get sent a cheque when you get to £50. Though this might take a while, sometimes there's only a survey every week or two. And there are quite a few surveys which are just a prize draw entry, though I've never won anything from them.
If you want to sign up to Yougov, I could send you a referral link which should get me a few extra points, let me know.