ETH mining could be a good choice if you know of tokens to buy with it.   If you only desire is to mine ETH and then sell it for dollars then there are probably better choices to get the best returns, however the advice for which coin is best varies every day or even every hour so its hard for us to say.

Also it depends on your wattage when mining each protocol, some people can get far closer to 100 watts then other people and that makes that particular coin a much better idea then something which takes over 200 w

Thats the problem with nicehash, it alters the protocol without asking and you will need to be changing the clocks on the card to match it best.  As far as CPU mining goes, its supposed to leave some spare capacity but you could also alter priority via Task Manager, just lower the priority of the CPU hash program so that your regular OS use does not suffer or the GPU usage even