I also do lots of compilation CDs, and I use Audiograbber. It’s freeware, and has a lot of advanced functions. It will normalize a WAV file, or will normalize an entire CD as you are ripping it, on the fly.
Furthermore, the “normalize” function is sophisticated. You can do the usual thing of setting “peak” volume to 100%, which isn’t very helpful if you have a song with a wide dynamic range of loud and soft. This softeware allows you to normalize by average, say, setting average output to 65%. That ensures that all your songs sound like they’re at the same volume and you are not constantly reaching for the voume control during playback!
It even allows compression, if you want to use it! Which is great for CDs you play in the car, because it will increase the volume of the “soft” passages!