Keynote:
http://webeffective.keynote.com/join/public/register.asp pays a $10
Amazon gift cert. for each survey completed. They're surveys seem to be very targeted for certain demographics (my DH gets much more than I do), so sign up all the members of your family for the best chance. We only get about 1 survey a month, but they're easy to do and the reward is emailed within 3-4 days.
Weekly Reader Insiders
http://www.wrinsiders.com/ is a good site if you have teens. They can earn gift cards or products pretty quickly.
Brandport
https://www.brandport.com/Webapps/index.aspx pays you cash to watch ads. I just started this one, so I don't know how fast they actually accumulate.
I also use Fatwallet.com for all of my online shopping. If you click on "Stores", they give a list of all the online stores that they work with and will pay you a % of your purchase if you buy through their link. I have used them since June and already have $48.00 accumulated. They will either pay via Paypal or mail you a check.
Not a survey site, but you can earn gift cards/products through Trainn.org
http://www.trainn.org/sites.php . It's basically sites where you sign up for free trials/etc and earn points towards stuff. I have earned 3 Xbox 360 games for DH at one of their sites for about $25.00 total. I also earned a $500gift card to Gamestop (
WalMart is also an option). I spent about $60-70 on sign ups to earn enough points for it, but I also got an additional $70 worth of misc. gift cards from some of those offers. We were able to buy BIL an xbox 360 and 2 games for Christmas for pretty much nothing. The big thing is to remember to cancel the offers you are signing up for.