The only free MPEG2 encoder I know is TMPGEnc, which in fact isn't quite free for MPEG2 encoding. Could you please list all the others you know? Preferably the ones which can transcode from AVI, are fast and give decent quality.
BTW, which is the latest version of TMPGEnc which allowed MPEG2 encodings without the time limit?

bbmpeg, not fast, but should give a decent quality:
http://members.cox.net/beyeler/bbmpeg.html
(i only did some dvd compliant streams with it - for some mini-dvds, so i never tested if it is usefull speedwise for something longer, probably not...)

http://www.hydrogenaudio.org/forums/index....25&#entry196941