Favorite is Kirk, both of them. I like Shatner's Kirk in the movies better than on TOS (he had a certain amount of cheese to him in the series, but matured well in the movies), and I like Pine's different take on Kirk. Both have good command presence.
Least favorite is Archer. I don't dislike him, but he seems to not have as much of a command presence, and also something about his mannerisms reminds me of George W Bush at times, and I can't stand GW Bush. Oddly, so does Trip~in fact if they ever do a movie about Bush, they need to get Conner Trinneer to play him.