ETH, Monero, Siacoin, IOTA, Golem, ripple are some of the well known coins which have a practical use. PERL coin came up with a good practice, the coin became opacity coin. What are the remaining alt-coins which have practical usage?
Don't forget to add Stellar's (XLM), for more faster payment solution and lesser fees, also COTI for Universal Payment Solution, I think many more altcoins has also a practical use case its just need a little bit study for its primary function to determined if it was applicable with our own uses.