I have been downloading music from mp3sparks.com in Ogg format at CD quality and then creating 192 mp3s with SoundConverter to play on my iPod. I want to continue to save high quality versions and burn them to CD for archiving, playing in the car, etc. I have the option of downloading in the following formats: Ogg, mp3, wma, mpeg-4, and mpc. What would the preferred format be? As I said, I want to save the CD quality version on a backup hard drive and also burn it to a CD in a format that can be played in my stereo. What format do I burn it to a CD in so that any car CD Player can read it?

Thanks,
Todd

Regular CD players use the .wav format.

What I do is save the original (high bitrate) version as mp3 then convert it to wav format using Audacity

Any codec will do, but for perfect quality, losses codecs such as flac are what you want. That said, you should use a regular codec, as there is no reason to waste disk space for perfect quality unless you really want it, a general purpose codec, while not perfect, is still close enough for most ears (especially if you think CD quality is high quality), codecs such as mp3 or vorbis are equally fine, especially if you use high bit rates (better quality, but still not 100% perfect, maybe 99% perfect). I wouldn't recommend the other codecs you listed because they are not as widely used as vorbis or mp3, especially, never use wma (microsoft formats have the worst supportedness with free software).

Try looking up results of transparency tests on hydrogenaudio. These are independent listening tests that compare various codecs at different bit rates. "Transparency" means that the compressed version of the file is indistinguishable from the original uncompressed version.

Personally I rip all my CDs using Vorbis aoTuV beta5 at 160kbps (oggenc -q 5), because I read somewhere that nearly all samples achieve transparency at that point. That said, if you have exceptional hearing and good hi-fi kit you might want to rip it at slightly higher quality, but there probably isn't much point.

The other thing to bear in mind is that every codec has certain weaknesses, for some particularly complicated waveforms you may hear artifacts at all bit rates, although is pretty unusual with modern codecs. I've never experienced it, but then my hearing and stereo isn't very good, and apparently it's more common with classical music, which I don't listen to.

Also, in response to J.W., I'm pretty sure CD players don't use .wav format (which is a M$ format). They use CD audio. To make a CD I use K3b (though other alternatives are also possible), using the "Create Audio CD" wizard or whatever it's called. Note that this doesn't guarantee that the CD will be playable on all CD players as CDs and CDRs are fundamentally different. Nearly all CD players these days will play CDRs, but occasionally you might find an old one that doesn't.

normal car & stereo CD players read Red Book audio format. Any decent CD Burning application should support burning audio CD's