As for captains, allowing for the era in which they were written, I take Kirk as the best. As one of the fivers says, it's a law of the universe that it's impossible for him to lose.
But eras really play a factor, both in our world and in the Trek universe. What was expected of a captain, what training and technology were available, what TV viewers expected of a great leader. Picard may be a better captain than Kirk in the same way that a decent major league batter today is better than Babe Ruth, but is that really the answer we're looking for? A general today has access to far more training, theory, and technology than Alexander the Great ever did, but only one of the two will be remembered by history. And as you say, it's also about personal preferences.
__________________
My 5MV webpages My novel fivers list
Yup
“There must have been a point in early human history when it was actually advantageous to, when confronted with a difficult task, drop it altogether and go do something more fun, because I do that way too often for it to be anything but instinct.” -- Isto Combs