Uhh.......... The best quality would be exporting as quicktime movie current since that's the native format. Might not be accepted everywhere though.. h.264 as quicktime is very powerful though.
Yeah depends on the final destination- web, tape, DVD, etc. In general, ProRes HQ is the format that will give you the cleanest picture with a manageable file size, but it is not something you put on the web or out on DVD directly.
If you're talking about pure quality, I believe "Animation" is what you'd use. My editing professor at film school says that it's unheard of to use for DVD or web output though because it will make the file MASSIVE. Like, super massive.