Definitely Ichigo vs Ulquiorra. The sheer epicness completely overwhelmed me. Ichigo vs Aizen was kind of disappointing. Ichigo vs Grimmjow was nice too, but I hated it when after Orihime cried out to him he just tells Grimmjow "Sorry, but I can't lose here", and cuts him as if he was never injured. I also didn't like it when he cut through Grimmjow's ultimate attack with pure determination. If pure determination is the solution to every fight, then its just not fun to watch anymore.