[cohoman]

You need to be careful when purchasing commercial video converters as most of them are repackaged iPod converters that create mp4 files. These mp4 files will play on the Zune, however, they might not have the exact specs to avoid the "transcoding" when syncing (which is basically reconverting of the file that could take hours). My suggestion is to test out their trial versions first and check for transcoding, and pick one that meets your needs.

If you want a freeware alternative, you can use Windows Media Encoder 9 along with a DVD ripper (DVDShrink or DVD Decrypter) to do the video conversion. I explain how I do video conversions on my web blog (see link below).