Premiere, recommended-so-often-I-lost-count, personally use it daily Mac OS X video transcoder VisualHub, which was a kickAsh front end to FFMpeg, ended development a couple weeks back amid much blog sobs and tears.
Good news now: It will live on as FilmRedux. So says Ars:
I have to thank Rene for letting me know about this app. When I made the switch over to a Mac a few months back I was clueless as to what I should use for my converting needs... this fit the bill perfectly.