What is the best file format to save my DVD's onto my computer for streaming?

I rip my DVD movies to my computer and then stream them to my TV's using media extenders. I've always done them in AVI format but am not sure that is getting me the best quality. I use Magic DVD Ripper and their tech support told me to try the MPEG-2 format. I did and while the picture quality it better there was no sound. Not sure what happened there. But anyway, what format would you recommend to try to get the closest DVD quality when streaming?