10. John de Lancie
Q makes a strong showing early on in the first season of DS9 in Q-Less, a continuation of his storyline with Vash (Jennifer Hetrick). This marks his only appearance on DS9. We don't get to see Q interact with a new crew until later in Star Trek Voyager. There are lots of TNG references throughout the episode. His on screen chemistry with the regulars and Hetrick was great. The idea that everyone outside of the crew of the Enterprise had been forced to attend briefings about him and that his old games wouldn't be tolerated on the station gave him a new dynamic.
9. Frank Langella
8. Julia Nickson
7. Jonathan Frakes
6. Iggy Pop
5. Tim Russ
Russ has played several characters in Trek and has appeared in all the television series set in the 24th Century (TNG, DS9, and VOY). He appeared twice on Deep Space Nine. His first appearance was in Invasive Procedures as the klingon T'Kar. He then went on to appear as the mirror universe version of Tuvok in Through the Looking Glass. Russ has done just about everything in the world of Trek. He had a minor role in Generations, lent his voice to video games and written comics for Star Trek. His next project is Star Trek Renegades.
3. Bill Mumy
2. Majel Barrett Roddenberry
What a lady. She must have loved Star Trek and her Trek family very much to do so much in the franchise. She appeared three times over the shows run. Her more outgoing character of Lwaxana Troi was a perfect foil for another uptight character in place of Jean-Luc Picard. Odo served as a great Picard replacement for her attention in DS9. I thought the most creative story out of her three episodes was Fascination. The Bajorian Gratitude Festival was gratifying for all of us that year.
1. Patrick Stewart
It was a tough call on this one, but I felt Picard's one appearance on DS9 in the pilot episode Emissary was worthy of number one. He beat out the 3 old Klingons from TOS that appeared in Blood Oath. For the first time we are getting a perspective of Picard from someone outside of his inner circle and crew that isn't positive. Even during TNG we didn't get a real sense of fallout from everyday Starfleet officers about Picard's role as Locutus. Sisko, a new character we barely know starts off with great anger and hostility towards Jean-Luc Picard for being responsible for killing his wife at the Battle of Wolf 359. We finally found someone in Starfleet who could care less about Picard and perhaps even wish him harm.
This makes for interesting chemistry. Not only does it further the story of Picard, it sheds light onto the nature of Sisko. I wish towards the end of DS9 there could have been an episode where Picard and Sisko finally come to terms with all the elements of these two characters that we only get to explore from these two scenes. Oh well. Star Trek has been good at sending off new shows with a little part of the old. Picard and the Enterprise starting off wishing DS9 luck was carried over to DS9 helping launch Voyager.
The scene that I appreciated the most was the Picard-O'Brien farewell scene that would often be cut from rebroadcasts of the episode in favor of saving time or making room for more advertising. O'Brien was a character that had grown a lot since Encounter at Farpoint and it was time it expanded even more. Here it is thanks to TrekCore.