mp3 is actually decent if you create the files with high (or variable) bit rate and set all of the parameters in your ripping software to their best settings.
As may be said elsewhere, mp3 is a lossy compression format, i.e. some information will be lost and the recreated play back may not be exactly the same as the original. There are other compressions that are lossless, i.e., you don't lose anything when ripping.
I have my entire library in high quality mp3, but finally, just to get with what my ears can't hear but my audiophile friends insist is better, I've started ripping in AAC (Apple Lossless). The format is fine and doesn't have DRM. I use iTunes for ripping the CD's and then playback on many players, Roku, Linux, etc. I doubt that I will re-do my entire library, but going forward I'm now using the lossless.
AAC files are a bit bigger than my mp3, but not excessively so. I do appreciate that I'm now getting as much as the CD provides, just in case I get into a listening environment that I can tell the difference!
