TMPGEnc is an excellent MPEG-1 / MPEG-2 encoder by Hiroyuki Hori. The encoder is extremely versatile, and is capable of producing MPEG for just about any need imaginable.

MPEG2 support is limited to a 30 day trial period, but you can purchase a commercial version of TMPGEnc, called Tsunami MPEG Video Encoder from Amazon that supports unlimited MPEG-2 encoding as well as various other features that the basic version doesn't have.