I love love love Valued Opinions! It's such an EASY survey site!
Participate in surveys, and when you reach $20, you can cash out for a gift card. Doesn't have many tedious and long surveys, as most of them are between 10 and 30 minutes. Keep your profile up to date to receive the most opportunities. When a new survey is available, they will email the link to you! You don't even need to log in everyday!