You want to be using a messenger based on Signal Protocol, no matter what. Nobody has thought more carefully about cryptographic messaging protocols than Trevor Perrin and Moxie.

It's good to have two secure messengers, one that favors usability and has a large user base, and one that can function as a laboratory for strictly secure UX.

The very secure messenger you should have should be Signal; as Trevor and Moxie and their team devise new cryptographic protections for things like contact lists and file transfers, you'll get them through Signal.

The more usable messenger should be WhatsApp or Wire. I don't have strong opinions about which; mostly, I'm just saying there's no other Signal-based messenger I trust at all.

Whatever you do, don't use Telegram.