Hitsugaya's Daiguren Hyourinmaru
Ichigo's Tensa Zangetsu
Byakuya's Senbonzakura Kageyoshi
Ichigo's New Tensa Zangetsu
Ichigo's Final Form
Gin's Kamishini no Yari
Sui Feng's Jakuhou Raikouben
If we had actually seen Tekken it would have my vote regardless of what it could do, but I'm going to have to go with Kamishini no Yari since its blade can pierce the heavens.
Ichimaru Gin's Kamishini no Yari, because if not for the Hougyoku saving throw Aizen Sousuke would have been slain by the great Shinigami Hero who thus never could be.
I found Sui Feng's bankai actually not bad.
Definitely Ichigo's Final Form. Though we didn't see much of what his final form can do i'm sure in the future we will have the chance .
Ichigo's final form. I never thought I'll see Ichigo as cool and calm as he was when he finally faced Aizen with some real 'Intent and Lust' for battle.
hitsugaya's!although he isn't very strong yet,he is too cool!especially if you add him icy wings and tail