Sierrahash
It is not best but good site for earning yet.
I can't say that how long this mining site work proparly, but til now I got many small payouts.
I invested 0.001btc and almost I got 0.002 and my earning is still continude till yet.
If you want earn small BTC and u are interested u can try this.
Try and earn more. Thankyou
https://www.sierrahash.com/?ref=6408