It took me most of my life to summon the willpower to sit through all of '2001', as I always seemed to slip into a boredom induced coma about 45 minutes in. But after finally seeing a couple of years ago, it's alright, looks very nice, sounds nice but is painfully slow. Watching a space air-hostess walk very, very slowly along a velcro floor isn't my idea of exhilerating/mind-expanding sci-fi ;-)
Also I always disliked 'The Shining' until I saw the longer US cut last year, which I loved. I'd rank Kubrick's films as follows...
1) 1957 Paths of Glory
2) 1964 Dr. Strangelove
3) 1975 Barry Lyndon
4) 1960 Spartacus
5) 1971 A Clockwork Orange
6) 1956 The Killing
7) 1980 The Shining (US Cut)
8) 1987 Full Metal Jacket
9) 1955 Killer's Kiss
10) 1968 2001: A Space Odyssey
11) 1999 Eyes Wide Shut
12) 1962 Lolita
13) 1953 Fear and Desire