For Droids lovers, who is best tank with them?

Zathrack

Who is best tank to be part of a deadliest Droid team, would appreciate if you are and Old droid player and you're between 70-80 level.

MalEliza

Royal Guard

In my opinion, it very much depends on the opponent. Vs slower, tankier teams Han is the way to go (as he will survive many attacks and gives turn meter for each). Poe is good if their dps toons are slower than Poe but faster than the droids. Vs speedy teams RG's auto taunt can save you. His stun is great, too.
Overall RG might be the most versatile toon, because he has the highest health and the AI can't really botch anything (such as taunting right before QGJs turn).