The most trusted altcoin is the one you trust.Today, the most trusted and profitable can be any altcoin, it all depends on market demand ,its capitalization and supply.
The altcoin we ourselves believe is not reliable in the market. The reliable altcoin is the altcoin that has great product and community and it's been developed continuously like XRP, ETH, XLM, NEO ... that's the altcoin that is reliable and and should invest