I thought it would be fun to name some actors that played different characters on the same series/universe (Like Star Trek)
The first one that comes to mind for me is the actor Tim Ware who played for different characters in different episodes of In The Heat of the Night tv show. A loud Mouth Redneck parent, a murderous Bounty Hunter, A murderous Banker, and Virgal Tibbs lawyer boss. He had a great line as the boss. "Morals are a great thing when you can afford them. And right now I can afford them."
Tony Todd who in DS9 played both Kurn (Worf's Brother) Forget the episode name and an older Jake Sisko in The Visitor.
Marc Alamo Who played Gul Dukat in Ds9 and Gul Macet in TNG episode The Wounded. (And he is the reason the Cardassians have neck Ridges)
I am sure there are tons of examples on Star Trek alone.
So what are some that you can think of.