No idea for a Mac, don't own one. If you own a PC, videora is ok (as long as you don't have a 64-bit OS). Xilisoft Converter 3 is the best I've found to date. Can batch converter by simply dragging the files you want/folder, and if you own a dual core or a quad core, it can do multiple threads. It costs money, however. I'm not sure how much it costs, as I "attained" it. I definitely recommend it. With my X3350 @ 3.6ghz, I can converter four 40-minute tv shows in 4 minutes. It's pretty impressive. Other converters took as much as twice that for the same show.