The best, as far as I'm concerned, is CDex, which lets you rip right to mp3 format, allows you to do variable bitrate as well as constant, from 32bps to 320bps and all the layers inbetween, .ogg format, and almost anything else you could want. it's fast, its layout is intelligent, and it's easy to use once you get it set up. The new Beta releases are usually out quickly (in fact sometimes it's hard to keep up with them) and I've only encountered one odd bug involving windows 2000 and variable bitrates, but it was fixed in a subsequent release, so the author keeps on top of it. The CDDB feature is great, and, in short, it's the one to have.
http://www.surf.to/cdex
Hope that helps you out! Oh, and if you're the kind that is willing to, make sure you get the latest Beta instead of the official release. They're both free, but the Beta always has more stuff.