Thank you for saying Citizen Kane. My wife and I rented it years ago after hearing all of the hype and thinking that we were missing out on something. And the end we were left scratching our heads.
Someone awhile ago on FR said something about how Citizen Kane was ground breaking with the use of lighting or something. Whatever.
I did the same with Lord of the Rings (wife was gone). Cranked up the speakers, moved the easy chair right in front of the screen with a soda and popcorn and got ready for an Epic Adventure in Film!! Fell asleep about half-way through.
I haven't seen Shane, but your other two were on my list. The category is "Most Overrated", not "Worst Movies". These movies were overhyped way way beyond their real entertainment value or significance.
Third on my list would be "Out of Africa". It was just dull and pretentious, yet won "Best Film" in 1985.