I marked rip everything, but I more or less agree with NP. If you are sure that you have a disc that you will never ever listen to, just get rid of it. If, on the off chance, you change your mind down the road about a song on the disc it's easy enough to acquire it, legally or illegally. But if you like one song, you should get them all. BTW, I digitized all my music years ago. One day, after about 4 or 5 years I looked at my CD collection, which was incredibly dusty, and I thought, "That's taking up space for no good reason. Why the ---fudgesicle--- am I keeping all of this around?" So I took it to a CD shop and sold it all. I was thinking I'd walk away with $30 or so. I walked away with $209, if memory serves. And they only bought maybe 1/3 of my collection. The guy helping me was a serious collector, and he was horrified that I was voluntarily parting with some of these CDs. For example, I had a Hendrix CD from before his family took over his estate and apparently had everything remastered or something. I don't remember. Anyway, after the CD store bought 1/3 or so of my collection I let him go through and take anything he wanted for himself. You should have seen him. It was like he had won the lottery. It was really fun.
ps I know that this was illegal.