Surveys that pay

I see a lot of suspicion around online earning sites, usually about PTC, PTR etc.. but sometimes about survey sites too. I use three survey services at this point in time, having dumped 'Ciao' some months ago - not that they are a scam, but their surveys take too long for little pay and sometimes you are answering questions for ten minutes until you are told you are not eligible for the survey.
In one Ciao survey I was sent, I could not beleive the way the questions went:
Question 1: Are you ....(my name).....?
Answer: YES
Reply: Sorry, you are ineligible for this survey!
(they sent this survey URL straight to my email inbox - they KNEW who I was!!)
At least they didn't waste much of my time, but I found that they would habitually send unsuitable surveys even when they were fully aware of my profile. That's enough about a useless service, let me tell you about the surveys that I DO take part in:

YOUGOV: Excellent service that will make sure that you recieve some payment even if you don't qualify for a survey. Payments vary from maybe £0.10 to £0.50 for a survey for your opinion was not required, £0.50 to several pounds for a completed survey. Their surveys are often of a similar type almost always multiple choice, rarely taking up much more than 10 minutes of your time. Payout limit £50 - it may take some time to reach this target - surveys are sent to your email address.
PUREPROFILE: Very similar to YouGov, although they tend to have surveys that you can complete via their website (at least when you first register), they also like you to fill out a lot of your profile so that they can send you relevant surveys. Payout at £25.00 - most surveys arrive via email.
DNEERO: My favourite by far, join by clicking on one of their survey widgets on this blog - their surveys are always VERY short and easy to complete, usually with about five or six multiple choice questions. They are unique in that you can get more earnings by posting a widget on your website, blog or myspace page, plus you can answer questions for small amounts using your 'Twitter' account - payout is just $20 and I think you get three-tier referral earnings too. Twitter opportunities must be sought out, but the normal surveys will be emailed to you.

All I would say is that with the more 'serious' survey services ie. YouGov and PureProfile, you should always be completely honest with your answers or just cancel the survey if you don't want to answer. The dNeero surveys are much more fun-focussed and do not require you to be so precise with your answers, there is more of a social/viral feel to the way in which dNeero carry out surveys.