Id say Minato. Im a Minato fan, but am by no means a fanboy; I can think rationally and accept when one character is superior to another.
Why Minato? Simply becausehe's far, far more intelligent than Bee.
If Bee doesnt start in Bijuu Mode, the fight ends almost instantaneously. If Minato was able to rip Tobi's arm off, an idiot like Bee, who is more obsessed about lyrics and rhymes than winning the fight, should be no problem for him.
If Bee starts in Bijuu Mode, and fires a Bijuu ball, Minato will just teleport the ball back towards Bee. As the Hachibi is HUUUUUUGE, it definitely wont be able to dodge the Bijuu ball, arguably one of the most powerful jutsus we've seen so far. This is Bee greatest jutsu fired back at him. This wont be[e] pretty...
Also, we've yet to see Minato's full arsenal of jutsus. People say he only has FTG and Rasengan. Its true that that's only what we've seen him perform, but thats due to the fact that the FTG-Rasengan combo works EVERY TIME we've seen him in action. Why fix something that isnt broken? (somewhat related analogy.) Minato isnt one to toy with his opponents; he wants to finish and move on quickly. And the FTG-Rasengan combo is easily one of the fastest combos we've seen so far.
Kakashi stated that to become a jounin, you must have affinity towards atleast 2 elements. Being a former Hokage, Id argue Minato definitely had 2, and as many Kages have 3, I wouldnt be surprised if he also did. That means the dude has A LOT of jutsus we havent witnessed yet.
Dont think Im saying Bee is a pathetic adversary- its just that Minato is in a different league to Bee. Genjutsu doesnt work on him; hes the perfect jinchuuriki. His sword skills are great (the guy fights with 7 swords ffs!!) His ninjutsu isnt too bad, and his taijutsu is great. Due to the Hachibi, his chakra levels are ridiculously high, and he has perfected Bijuu Mode.
But against someone of Minato's intelligence, and his [assumed] huge arsenal of jutsus, I see Minato winning. But it wont be easy...:shrug:
:scorps: