FileBot is the ultimate tool for renaming your tv shows and downloading subtitles. It's streamlined for simplicity and it just works. FileBot supports Windows, Linux and Mac, plus there's a full-featured command-line interface for all sorts of automation.

Video Demo:
http://www.youtube.com/watch?v=zcSFKiwFLZw

Support Forums:
http://filebot.sourceforge.net/forums/

Download (Intel Mac):
http://filebot.sourceforge.net/download.php?type=app
Download (32-bit Windows):
http://filebot.sourceforge.net/download.php?type=msi&arch=x86
Download (64-bit Windows):
http://filebot.sourceforge.net/download.php?type=msi&arch=x64

All Downloads (Windows, Linux, Mac, BSD, Solaris)
http://filebot.sourceforge.net/#download

Change log

2.5 New features:
+ Support renaming/moving of disk folders (BR, DVD, VCD, etc)
+ Improved movie auto-detection / matching
+ Improved support for date-based shows
+ Customizable episode sort order (Airdate, DVD, Absolute)
+ {info} binding for all sorts of series / movie info like director, genres, certification, rating, etc
+ Support ascii-conversion in naming scheme {.ascii()}
+ Java 6 backwards-compatibility for scripting (filebot -script …)