The ones here: Bing Rewards - Redemption Center
If you use bing for searching, then you get points that you can use for entering different give-a-ways, donating to charity, and gift cards (what I do).
I average a $5 Amazon GC every month. I tried a few sweepstakes and realized that I never win anything, so I might as well go for the sure thing!
save your points to buy gift cards.
Im a user of swagsurvey. Another way to gain points.
500 bing points gets you 500 swag points. An 450 swag points equals $5 amazon gift card.
So automatically you save 50 points and you get an additional point source income
Bing just notified me that I won one an Xbox One with Kinect Sports. They say I should receive it in 8-10 weeks. I have never won anything besides an office pool. I would prefer to win a Surface 2, but I'll take the Xbox One. I put in about 350 entries. For proof, when they announce the winners, my name should show up as Joe S. under the winners.
I've blown at lease 300 points on XBOX ONE and WP offers. Havent won anything. Other than that I go for the $3 store credit for apps/games and XBVideo movies.