I have a fairly large collection of laserdisks, mostly bought when they were being sold off at 4 quid a shot by the main UK distributor.
About the most treasured is one called "Triple Tribble Trouble", which has "The Trouble with Tribbles" and the first half of the animated story "More Tribbles, More Trouble" on side A, and the rest of the animated story then the DS9 episode "Trials & Tribbleations" on side B.
As far as I know it isn't available on DVD, if I'm wrong I'd love to know. I really don't want to buy the season collections when there are only a handful of episodes I like that much, this particular theme disk has two of the four or five episodes I really like. But my laserdisk player is getting old, and nobody has them for sale any more, sooner or later I'll have to do without.
I could get it copied onto DVD for myself but I suspect it'd be crap quality and expensive, and my DVD player is so old I'm not even sure it'll play recordable DVDs!