(Thorium) Best Classes for a Duo?

Me and my friend have done a couple runs of terraria. A vanilla run and a calamity run. Both times we went melee and ranger and now with the other classes introduced in thorium, we were wondering what classes have amazing synergy for a good playthrough. We were wondering if the bard and healer class are any good together, or any good by themselves for a 2 player run.