Root: Vagabond: I enjoy how this is such a different style than the other three in the base game.
Gaia Project: Ivits: Just very clever encouraging to make a close nit Hivemind rather than spreading out, it's very satisfying every time you hit a new federation milestone.
Scythe: Polania: I just like exploring and claiming as many encounters as possible around the board.
Terraforming Mars: Ecoline for Solo Play: The extra plant just is a load off for my solo games where I don't always have to worry about focusing on oxygen so much and Ecoline feels like I have more freedom over what cards to pick.
Apiary: Iber faction, when upgraded you can retrieve a worker each turn and gain farm income if you spend a resource. Super powerful. Maybe too strong.
Black Rose Wars: Chronomancer is RAD. Playing cards from hand is just awesome.
Terra Mystica: Witches. Flying around to forests and dropping dwellings is great
Circadians First Light: the lady who doesn’t need algae to send out her ships, I forget her name
Deep rock Galactic: Gunner. Unloading 4 ammo in one action to do up to 12 dice worth of damage is beastly, especially if Scout popped a flare for you