Digital Media Converter
For you, dear reader (and my writer's fee), I persevered. Though the program is way too reliant on external codecs, it's easy to use and produced good results. The demo version watermarks video, and for longer files it places the first three minutes of audio in a separate audio-only file, but it gives you a good idea of the quality of the quite acceptable transcoding. The program didn't like my HD files--complaining about bit rates, it did import and convert Real Media files to other types after I installed the Real Alternative 1.60 codec--despite a file open dialog without a *.rm, *rma, etc. template for loading them. This leads me to believe that it might import any type of file for which you have a DirectShow filter, though I attempt it with any others.
All in all, Digital Media Converter is worth a try, though the price tag is hefty. And you might want to apply the money to a multimedia suite which will do the same thing and more.
--Jon L. Jacobi