Best Crypto to mine with GTX 970?

Hey all,

To start I'm aware its a rubbish card these days but I'm just testing the waters I'm living at home to electricity isn't a worry or anything and I barely use my pc these days so I figured I'd put it to some (limited) use.

I'm just wondering what cryptos I could mine to gather some coins whether profitable or not.

For example, last night I mined my first ever coin (as slow as it was) which was Siacoin. After 16 hours (evening and overnight) I gained 38 at avg 800MH/s and the payout wall is 500 which I'm going to leave my pc on to hit (even if it does take nearly 2 weeks).

What other coins could I try to mine? I read about ethereum and people hitting 20MH/s with this card but what kind of return even is that? 0.0001 every month or something? (I have no idea how to work it out) nor do I have any idea how to even set it up to even try it(if someone could point me in the right direction)

I also was told in another thread to try NiceHash, has anyone ever used this?