CBanks,
Excellent point about Citizen Kane being clinically studied like Shakespeare instead of being enjoyed. I watch Kane about once every two or three years or so, and I'm always amazed, not only by how brilliant it is (that's pretty much a given), but also by how funny and entertaining it is. But many people don't pick up on this aspect of the film, perhaps because by this time the loftiness of it's cultural standing approaches that of the works of Shakespeare. As Michael Anderegg points out in "Orson Welles, Shakespeare and Popular Culture", Welles spent a good portion of his career trying to bridge the gap between Shakespeare as academia and Shakespeare as popular entertainment. Charles Foster Kane strikes me as a very Shakespearean protagonist.
One last note on 2001: it reminds me of Kane in some ways, not just because of the end where the astronaut lives out the rest of his days a virtual prisoner amidst elegant surroundings, but also because both films center around an object as a source of mystery. I like to compare what Welles did with Kane to what the monolith did for the apes. Welles raised the film world's intelligence level by showing all that could be done with a camera the same the monolith showed the apes what could be done with that bone. Maybe that's another reason why Kane is still considered the greatest film.

