So far we've seen Tousen's bankai, but have yet to see Gin's. Considering this, who would win if the two ever fought? I'd have to say Gin because Tousen lost to Zaraki even with his bankai. Also, Gin seems to be more ruthless than Tousen, so I imagine him winning.
If you've been keeping up with the manga, they do finally reveal Gin's bankai,
it has the capability of 'extending' and 'contracting' super long or super short distances in milliseconds. Of course this is later explained as Gin's blade merely vaporizing and re-materializing at will.
As a matter of who would win, Gin I suppose.
No, I just watch the anime. I'm going based on that.
Gin's Bankai is just like a better version of his Shikai. I think Tousen would win against Gin.
I hate Tousen, his name is cool and all, but Gin would grind him into the ground.
and, you forgot to mention that his Bankai also has FRIGGIN POISON! on them!