Many of those are full seasons of TV shows on DVD. Those have their own shelf, separate from the movies (The Frighteners goes on one shelf, the first season of Lost goes on another and so on).
So, here's the issue:
Serenity is my favorite movie. When asked, I mention it in the same breath as The Lord of the Rings. Indeed, despite being a Browncoat before the hype really started up, I can appreciate Serenity as it's own film, independent of Firefly.
So... which shelf does it go on?
The X-Files: Fight the Future is on the (overflowing) TV shelf, nestled in it's cannonical place between seasons 5 and 6 of The X-Files. In contrast, Cowboy Bebop: The Movie sits on the (also overflowing- I love movies) movie shelf while the collected volumes of the Cowboy Bebop series are on the TV shelf.
So do I count Serenity as film independent in it's own right, or place it after Firefly as the cannonical continuation of the series?
Oh, and I was lying about the cookie and nickel. None for you.