With so many series to consider, this is not an easy question to answer. In the end, my choice goes back to the original one with James Tiberius Kirk, Spock, Scotty and 'Bones'. I was going to pick the fantastic performance put in by Dynasty stalwart Joan Collins in 'City On The Edge Of Forever' but finally had to go with 'Kahn' from 'Space Seed'. Yes, for me, the best ever is that wonderfully talented hunk Ricardo Montalban.
How about you? You can pick from any series you like - even 'Star Trek - The Next Generation'!

I liked Roger C. Carmel as Harry Mudd, myself.

Whoopi Goldberg

My favorite guest stars were The Village People, in episode 21a. They played in the band at the Mos Eisley Cantina when Captain Kirk tried to stop McCoy from hiring a ship to help him smuggle adult holo-programs to Tatooine, so he could trade them for illegal self-sealing Stem Bolts. I guess that was my favorite episode.

My other favorite starred James Spader early in his acting career. In that episode, Commander Sulu’s “significant other” got drunk on Rommulan Ale and he programmed the Holo-Deck to recreate a 20^th Century law office and courtroom so he could frame Harcourt Fenton Mudd on trumped up Tribble smuggling charges. That was also the episode where Wesley Crusher killed Commander Worf in hand to hand combat.

Anyway, Spader played the part of a holo-lawyer, programmed by Star Fleet, and he and Shatner had to clear Mr. Mudd of the bogus Tribble smuggling charges lodged against him.

Steven Hawking as himself.

You're nearly as naughty as me!

my picks are Ricardo Montalban and Joan Collins iam a pretty big trekie