On Nvidia the best thing to do is to aim on Equihash, Daggerhashimoto (Eth like crypto) and Lyra2REv2 (monacoin), Amd can get better hashrate on DaggerHashimoto, Cryptonight (Monero like crypto) and NeoScrypt, (hint, right now a lot of NeoScrypt coin got a big pump, look for TrezarCoin, Vivo and Feathercoin. So, ethereum is a good choice with your rig, but in my opinion, you better look for the ethash coin with a good marketcap and a good H24Volume and aim for the one with the lower NetworkHashrate, in order to claim more coin, to hold for a bit