No doubt the best cut exists utilising a mix of Donner/Lester footage.
Personally I don't enjoy Lester’s version very much. I did make a fan edit from the RIC of S2, and was just enthralled by how great a movie Superman 2 can be once you take out the Lester comedy and add some Donner magic.
I haven’t seen the Donner cut yet, I’m patiently waiting for December 6th the Australian release date for this highly anticipated release.