I think, Monero, Litecoin, Ethereum, these coins will stay for long, may be for life. We will get a lot of coins in future. May be we will get even better coin. but it seems these 3 are valuable. they have large community support, active devs teams, large market cap, extensive trading volume. Over all they have large potentials. IMO they are leaders. If you have any other coin in mind, help me by sharing your opinion