I have tried all, and the most profitable mining for GPU is contellect right now. They have a weird payout scheme , but they pay way more than any other pools.
For instance you can get 1.2 to 1.5 EURO/day with 1 good card, but will get the same with 3-4-5 cards
, they pay like a maximum of 1.5 EURO to any mining power under 10MHs but over 0.5 MHs (scrypt mining). To withdraw, you can do it via dogecoin , paypay and cryptopay (i think), I have made all my withdraws using Doge, the thing is if you let your earning accumulate, they ask "verify you", and this is done by credit card ( for security reasons not recommended) and by buying one of their mining contracts, I bought (using Bitcoin) the 15 EUR contract and got 17. something EUR back. Been mining there for over a month, great profit. I don't know if it is scam /ponzi /whatever or not , but I have made a profit.
If you need help PM me