Nearing the end of the game it's me as a barbarian, Astarion, Gale, and Wyll. I've got Wyll up to 24 Charisma so he is an Eldritch Blast machine and Counterspell backup to Gale, who is the utility spellcaster. Astarion gets swapped out when someone else is needed for plot.
I use a lot of healing potions and tank a ton with my raging bear totem barbarian.