I like Picard better than Riker (though I still would have loved to see how the show would have gone if Stewart had left after BOBW and Riker remained captain), but Worf was always my favorite character.
My favorites were probably Bashir and O'Brien (I won't include Worf since he's already my favorite in TNG), but Sisko was of course awesome.
Janeway was never my favorite, though I never particularly disliked her. I watched the show because of the Doctor, followed by Seven, Tom Paris, and Tuvok.
My favorite characters were Trip, Malcolm, and Phlox, followed by Hoshi and then T'Pol. Archer only beats out Mayweather for me, and that's only because Travis was boring.
I never really got into TOS, but I'd probably put McCoy ahead of Kirk, followed by Spock.