Kirk- Angry guy probably taking too many testosterone injections. Likes to assault women and generally just makes some of the worst decisions of any star trek captain. If he just listened to Spock he'd avoid 99% of the problems he runs into. Constantly endangers his crew by being overly violent and getting locked up or his crew punished.
Sisko- Another overly emotional captain except he actually makes good decisions. Needs to keep his anger in check. Does not know how to parent whatsoever and he's way too much of a risk taker for a dude in command of a fucking space station.
Picard- God tier captain. Makes all the right decisions. Emotionally balanced. Solves the problems of his crew. Basically perfect in every which way and as thus is one of the most accomplished captains in the Federation. That's why they put him on a top of the line, cutting edge star class cruiser. He deals with time warps, worm holes, alternate dimensions, new species, and just about anything else you can throw at him, with GRACE.
Picard is the best star trek captain of all time. Change my mind.