Ever heard of Ethereum my friend ? It would not be wrong to call Ethereum the best Altcoin. Ethereum is the most promising, highly sophisticated and highly demanding altcoin. Many tokens are developing using Ethereum blockchain and that's is the reason ethereum will probably increase in value and will be highly demanding in future. Ripple, Monero, Zcash and Litecoin are also investment worthy coins.
Ethereum is not a coin nor a currency, it's a platform. Ethereum is used to create, not to buy, to buy created tokens but not as a general purpose currency.