Definitely Ichigo! He beat Aizen!!!

I would want ichigo to win but Yamamoto is very strong...

I would prefer it if Genryusai Yamamoto won a fight against Ichigo... He is the Head Captain, if he lost, that would seriously decrease the morale for the Gotei 13. Plus, there's no way Ichigo would ever win against him, he is simply too inexperienced.

I'd just want Yamamoto to win to put Ichigo in his place. At this point, Ichigo feels practically immortal, bout time someone showed him what's what.

I doubt Ichigo could handle Yama-jii if he released his bankai

Hmm..I would love to see Ichigo-kun win but Yamamoto-sama is very strong..so hmm what I want and what might happen could be two different things..

Okami46, yes, he did beat Aizen, but then he lost his Shinigami powers and the new form he had obtained. Yes, he probably would have beaten the Head Captain in that form, but in his normal Bankai, he would have no chance against the Head Captain. Yamamoto-sensei would be able to defeat Ichigo without even needing to release his Zanpakuto, that's how powerful and experienced he is... Ichigo is new to the Shinigami thing, compared to him and the Head Captain has obviously studied every way of fighting possible and would read Ichigo's moves like a book.