I saw there are a lot of topics about undervalued coins, but I did not find any about overvalued coins.

I hope everyone agree that there is no point to talk about some pumped crap. So let's only talk about coins that should have real value, but for some reason are overvalued right now.
As for me, I think the most overvalued coin today is Ethereum. I don't understand why does it cost so much. It is not decentralized. It is not limited, so there is no deficit. Nowadays it doesn't look innovative. It is not even great as a cryptocurrency. Of course it is great for ICOs, but most of the ICOs are crap.

Most of this coins will die in future. So it's just a hype and nothing more.

HOLY hell, you're new here as i can see. Yeah, Ethereum was the first to implement smart contracts - it's not a hype coin. It was the first coin for making a blockchain for other coins to be used in its protocol. If anything ETH deserves its value. Ripple on the other hand - I can say a lot more of when talking about over value. Please do your research.