(It's impossible to do it with the new characters in The Good Fight, not at this early stage)
Here we go!
Kalinda Sharma: A slytherin to end all the slytherins! Queen of self-preservation, cleverness and cunning.
Will Gardner: GRYFFINDORRR. I mean, obviously: the Chicago Defense "Show me a map and I'll show you where you live", the literal table flipping at Alicia, the occasional yet effective puppy eyes, "MY PLAN IS THAT I LOVE YOUUU, OKAY?!" (That would also explain the ultimate tragedy of Willicia as an issue of communication between people who live by different basic values)
Diane Lockhart: Gryffindor. Idealism, bravery, talent. The Minerva McGonagall of Chicago law.
Kurt McVeigh: Ravenclaw.
Cary Agos: Slytherin. <3
Eli Gold: Also slytherin. (It's hard not to find them on this show)
David Lee: THE MOST SLYTHERIN.
Finn Polmar: A darling Hufflepuff.
Elsbeth Tascioni: She's basically the Luna Lovegood of the show, such a clear Ravenclaw (Although, I don't like the fact that they are pushing on the strangeness of her behavior. It feels like overkill. Yes, Elsbeth is strange and unusual, but not a just a comedy insert for the sake of an easy laugh)
Grace Florrick: A Hufflepuff, possibly?
And, of course, the protagonist. Alicia Florrick. Slytherin, I think. (Although she's so complex and layered, I could be persuaded with a Slytherclaw or something like that too)