I have been a member of lifepoints and it's previous incarnations for many years and it is one of my favorites. Plenty of survey opportunities to participate in and easy to navigate. They do charge £1.50 admin fee when cashing out though which others do not although the payout threshold is low at £10
I have been a member for many years steadily earning around £40 a year. Very average site, that is until you need to contact them. You can only do so by email and they responded once with an automated message then nothing. SIX months later still no joy and money is lost. Please avoid!