Best heroes to upgrade

I have a lot of heroes I want to upgrade, but I’m not sure which one is the best. Gold 4, level 60, and 6 stars is my goal for the moment. Any ideas?

Can never go wrong w metas… Drake, Flat, Caine, Ronin, Mauler, Min, Dog.

Dogface and Maven
Or Halo

Plat Halo is always a good choice