As said earlier, the only one I know for now is freebitco.in, who pays 4,08% a year interest if you let more than 30k satoshi balance on your account there. Actually they invest part of it in mining and share their profits with you.
One of the best bitcoin wallet that I know that pay interest for keeping money is the coins.ph. Coins.ph is an online bitcoin wallet in where you can invest and keep your money and it has the ability to grow when you make transactions using your bitcoin. You can gain interest for the money that you kept.
Coins.ph seems reserved to the Philippines