I am currently on Episode 24 of the first season and I have already noticed a great cast of supporting and guest actors on the show! A lot of familar faces for sure and some recycles, but I am very pleased
I've been seeing some of my favorite actors on the show, and it's still the first season!
There's a number of familiar faces to come. The Vissian Captain in "Cogenitor" should look rather familiar to you. So should the female Andorian in "Cease Fire". DEFINITELY the Klingon lawyer in "Judgment" and the non-Tellarite bounty hunter in "Bounty"!
Without really spoiling season 3, I can tell you that pretty much all the actors who play the Xindi have made other Trek appearances before, most of them several times.
As I said, I think, after a while, spotting actors you'd seen in other Trek appearances is part of the fun.