I have a relatively large collection (I'd guess between 2 and 3,000 discs). Unfortunately I've never watched at least a hundred of them. I don't like to watch something I've never seen before unless I can give it my full attention. And most nights I'm too irritated from work to actually concentrate. So I end up watching replaying something familiar.
I really look forward to October and the Horror Digital marathons because I make time to blow through a large number of the flicks in my "need to watch" pile. Too bad there are 11 other months in the year.