MyPoints has the most diverse way to earn points. Plus, it's connected to a lot of retailers, which means there's certainly a gift card with your name on it somewhere.
YouGov is a survey site that focuses on your political views as much as your shopping habits. Like most survey sites, it's a lot of work for a little reward.
Acorns are apparently a way to confuse you about how much you're getting paid. For instance, I filled out a survey about myself for 10 acorns.
As of this morning, I have made a grand total of $8.72, but I can't cash out until I reach $30.