My physics teacher once made us watch "2010" on the last days of one term.
I saw it knocking around on DVD recently, but it was simply a direct lift from video, so I left it.
"2010" was a good film - an enjoyable film - but really I'm not sure that "2001" ever
needed a sequel. My suspicion is that the sequels were derived primarily for commerical, rather than artisitc, reasons.
No doubt that will cause unintended offense to the Clarke fans - I am merely hypothesising here.