I voted for ESB, almost voted for "A New Hope." As far as I'm concerned, he didn't touch the movie but to add the E4 title, therefore, calling it ANH is just as valid.
I really did enjoy ROTS, though. That's about tied for me, but ESB easily wins out because it has Han Solo, and the Lightsaber battle at the end of it carries even more weight, due to Luke being an underdog. Whereas, the final fights in ROTS, Yoda/Emperor and Obi Wan/Anakin are evenly matched.
Probably my favorite part of the Lightsaber fight in ESB is after the group gets away in the Falcon and Luke's is taken by surprise by Vader, and Vader just cuts loose and really goes at him. The look on Luke's face when Vader tells him "You are beaten.... it is useless to resist" really tells us that he's emotionally and phyiscally exhausted. The circles under his eyes..... he looks totally worn out.