My favorite Altcoin is the Binance coin (BNB).

Reason being that:

1. It help users provide maximum security for their funds, by reminding you to check that you are visiting the right binace website before login, after which the Two-factor authentication is used and the interphase makes it kinda mandatory to enable at least one (either sms or Google).
   Provides API documentation which enables you restrict access to trusted IPs only, the setting which can only be accessed by entering the API key label along side the 2F authentication code.
2. The fact that the Binance interphase allows the trading of other Altcoins not restricting the exchange currency to BNB only.
3. The strategy that offers 50% discount when BNB is used to pay fees.
4. Verification of account only after some vital documents are being scanned, uploaded and approved.