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?
Practically what do you mean? If it is practical for daily needs, I think large altcoins like ETH, IOTA and Monero are still very feasible to be used as alternatives to exchanging with bitcoin because the transaction costs are cheaper than bitcoin. However, if the use is universal I think ETH is still very good potential for that, for example there are some marketplaces that have received payments using ETH.