***Update: Use Nicehash excavator or Claymore dual miner.
To mine Ethereum, you must have a minimum of 2gb of vram on your GPU. The new generations of cards for AMD (Rx470/480) are very power efficient and we recommend them for ETH mining. NVIDIA is very power efficient too, but has a higher initial cost. In any case, we recommend these miners.
- Genoil Eth miner. Genoil is a very generous person, and if you use his miners please donate either bitcoin or gpu power to him. Without people like Genoil the crypto community is nothing. Please see his thread here. Free. (not recommended)
- Claymore Dual ETH Miner. This miner is not free, and has a 2% fee if you dual mine, 1% for ETH only mining. The fee is automatic (the pool switches to the fee pool once an hour). You can dual mine Decred (DCR), SIA or LBRY. In general you may get 10% more profit but this is highly variable and depends on the value of the dual coin. See here. Current version is 7.4 (recommended)
- For more advanced users, there is also sgminer with updated ethash kernels.