The Extraordinary Adventures of Adèle Blanc-Sec is a curiosity that I do love for it's steampunk look. It's a fairly light touch but it does work in the way that only the French seem to be able to do... Delicatessen is probably my favourite Steampunk but it is more Dieselpunk as it is supposed to be post an apocalypse... Brazil is probably the same... In my view it's the best film of George Orwell's book 1984...
Just recently watched The Extraordinary Adventures of Adèle Blanc-Sec, and I have to agree with your assessment (and it's just all around an enjoyable movie).
And speaking of French films, there's one called Vidocq that I'd say is a must-see if you're looking for a good Steampunk movie (but that's just my personal opinion).
Kind of a weird one. I watched it with my kids today. Atlantis the Disney movie. There were some aspects of steampunk and my kids really seemed to enjoy it.