The Amazing Screw On Head if you don't mind animation.
The Mysterious Explorations of Jaspar Morello is a good one as well. It is a short.
You could probably get away with
The Red Baron (2010) or
Flyboys airships and all.
I'm a closet steampunk, I enjoy the anachronistic style. However, I tend to differentiate it more from Dieselpunk which is similar but more art deco and of course diesel and gasoline being the main fuel source. I see WW I as the kind of transitional cut off point with movies. As the Victorian era really died very much in style as that war went on. However, that doesn't limit based on your thoughts of what qualifies and doesn't qualify.
http://brassgoggles.co.uk/forum/index.php/topic,13126.0.htmlThat should take you to the Brass Goggles list of steampunk movies and is pretty full from what I recall. It is also nice to lurk around if you want to see what is upcoming in the genre and thoughts from within as well as ideas.