As "The Great Mouse Detective" was the first Holmes adaption I was exposed to, I thought it deserved an appreciation thread.
It's a very good adaption too, for a kids' movie. I haven't seen them all by far, but of all the incarnations of Holmes I have seen, Basil of Baker Street is one of the closest in personality to BBC Sherlock. There are some funny parallels between the movie and the show (many of which are based in ACD canon, but some not).
Both characters are dramatic, operating outside of social norms, and some semblance of Not So Stoic; by which I mean they are both emotional but keep their feelings buttoned down in true Holmes form, until there is a rare display of compassion or caring.
Ratigan (Moriarty) is equally dramatic and dresses like royalty at one point.
Basil and Dawson (Watson) go undercover disguised as sailors. ("He wanted to be a pirate.")
Basil can never remember Olivia's last name. ("Is that why you're calling yourself 'Greg'?")
Interaction with a child.
Some think that the scene in HLV where Mrs. Hudson identifies "behind the clock face of Big Ben" as one of Sherlock's bolt-holes is a nod to this movie.