Sisko for all the bad-ass things that he's done and mentioned for. But Kirk gets the nod because Sisko wanted to meet him face to face before heading back to the future. Now that's respect And also for General Order 24.
After hearing all the arguments I have to say Sisko. I remember the episode when he punched Q. He didn't take any of his shit. BAM! POW! BLAMO! It takes some cahonies to punch a god, but then again you'd be pretty stupid for doing it...
He has more on his plate. It's tough to be a badass, an explorer AND a problem-solving diplomat. For pure badassery maybe some other bald guy could run him a close second. Two words, though: Red shirt.
Only five minutes of screen time and he's doing what he's doing what he's doing? Robau works in mysterious ways. Repent, heathen.
Sorry!! Here it is again [yt]http://www.youtube.com/watch?v=wqdFYQDSB5E[/yt] Remember 5:50 to around 6:20 to see why sisko is the most badass captain