I use e-Rewards and MySurvey. They are both free and don't spam you. If you are wanting to make a lot of money or get a lot of gifts, these won't be the websites for you. It can take a while to build up some points, but you'd be surprised how fast you can do it. e-Rewards is more limited when it comes to rewards, but I use them every year to redeem for Skymiles, so it is worth it to me. You can customize your preferences on how many survey requests you get a year. I have it set to maximum and I get an invitation for a survey at least once a week, if not two or more a week.
MySurvey is also really good and has sent me a bunch of product samples to try, completely free, no fine print. I have gotten packs of diapers, wipes, yogurt, formula, toilet paper, etc. You take a survey at the beginning to see if you're in the demographic they need, they send you the sample to use, and you take a survey at the end to tell how much you liked/disliked the product. MySurvey also just revamped their rewards. You can redeem points for a check or prizes. They have some really cool stuff on there, but I have found if you compare the price of the points for the reward to the price online, you'll usually find it cheaper online. For example, 1100 points=$10. I found a camera case that could be redeemed for 2200 points, so $20. I found it on Amazon for $13. So I bought it on Amazon, redeemed my points for cash and was still happy. These are not huge moneymaking sites for me, but I get enough survey invitations to keep them going. Hope you get some good sites.