i say kyorakus bankai. It's very unique and great which is cool.
His Bankai hasn't been shown...unless you mean his Shikai.
Omaeda'shikai is disappointing, but it's a normal melee-type, so I don't see what's weird about it. Oh, and the fact that ichigo's bankai is compressed, rather than large-scale makes it kinda weird, I guess.
i would say ukitakes shikai the fact that it is able to absorb the opponents attack and send it back to him it is pretty interesting. and i think that it is weird also because we still dont know if it can only absorb energy blast type attacks also for example absorbing yamamotos flames and sending them back to him
but i think people like kyoraku and hitsugaya's zan are cool, hitsugaya can change weather (he can make it rain! lol) and kyoraku's is just genius hiding in shadows come on it dont get no better also love kiras