Near the end of the tenth and final season, as the show began to broaden its scope of material again, one of the episodes "riffed" on a heavily cut-down German production (dubbed back into the original English) of William Shakespeare's Hamlet, starring a young Maximilian Schell as the Prince of Denmark. There seem to be plenty of people who don't find the end result very funny, although I've also noticed that positive comments about it seem to turn up fairly often in the mst3k community whenever the topic turns to "underappreciated episodes" or the like. I did see one interesting comment that the show ought to be allowed some experimentation in its final days.
As for myself, the lengthy Shakespearian dialogue at times seems to hold off quips by main force, and at other times stands in stark contrast to those quick, casual comments. The "riffing" generally doesn't seem that mean-spirited to me, though, although perhaps impatience may be making it a little bit that way by the end. (There are at least some good, memorable comments in any case. I did once come across an audio file made up by someone that used the riffing of the "To be or not to be..." soliloquy to take on William Shatner's version...) I did find myself taking in the bleak, possibly expressionistic, certainly minimalist sets of the production and contemplating how the assorted foreign and dubbed movies Mystery Science Theater featured often offered a greater visual scope than the cheap domestic productions it also included... but not so much in this case. However, the "host segments" provided, for me at least, an interesting tonic to the occasional and now somewhat unsourceable complaints that those little sketches somehow "weren't addressing the movie" in the later years of the series.