This is a tough one.
Picard, as a DIPLOMATIC tactician would win this hands down. But in actual combat, beside the Picard Maneuver, doesn't really stand out tactically. Even Riker seems to have him on the ropes in a 70 year old ship.
Kirk, likewise, is full of bravado and a great bluffer. His confidence is what wins his scenarios...not sheer tactical brilliance.
So for me, this is between Sisko, Janeway and Archer.
Archer used an inferior ship to defeat enemy vessels quite a few times and did it unsupported. His tactics in the Xindi conflict were crucial and a success. However, he does some times seem out of his depth. Im unsure whether to blame him or the inadequate ship.
Sisko fought the Dominion and was frequently shown to be cunning, though also quite reckless. His ship, and its unique design certainly seemed to favour him.
My vote, however, goes for Janeway. She has bravado too, like Kirk, but she fuses it with a guile that I admire. She has frequently tactically outwitted numerous captains/species and is an expert at turning a situation to her advantage [while usually hiding that fact from her foe]. She played the Borg when she needed to, placated 8472 and has multiple space combats where she had dreamt up something quite exceptional.