I think that the Extended Edition of Fellowship is the only one that is clearly better than the Theatrical version, simply for the extended departure from Rivendell, farewell to Lorien (seriously, it’s probably my favorite scene in the films), and even the extended introduction to Hobbiton.

The Two Towers benefits from the Boromir flashback, and if that wasn’t there I would just watch the Theatrical version.

The Return of the King is far better in Theatrical form. Aragorn and Co. wading through a sea of skulls was a Jump the Shark moment for me.