I thank you all for your replies!

I guess pretty much anything would be profitable with my electricity rate.
I'm leaning towards mining ethereum on GPU, because in my opinion Antminer S9 may become obsolete quite soon.

I have one more question. Does mining ethereum on GPU requires a lot of traffic?

I live in Russian Federation. Standard electricity rates here are around 5-7 cents.
There is a hydropower plant in my city, which is why the electricity rate is that low.

Hello, everyone!

I discovered cryptocurrencies for myself just recently, so I'm a little late for the party  
Anyways, I am interested in mining cryptocurrency, but I am not sure which cryptocurrency has the highest return in usd.
Also, which hardware would provide the highest return on investment?

I have read a few threads over here, but I couldn't find all the answers to my questions.
I realize that cryptocurrencies are very volatile, which means that my return on investment will change as the time goes on.
Mining bitcoin does not seem the best option to me, but I may be wrong. I would like to hear your opinion on which cryptos are best to mine now, and which of them are expected to rise.

Any tips for a newbie miner are apprecited!

P.S. My electricity rate is about $0.018. I think it's a pretty good rate to mine cryptocurrency