Based on the combo' used by a lot of Sqeezebox users, I'm using Exact Audio Copy (EAC) with AccurateRip. EAC was a pain to set up, but things are running pretty smoothly right now, so I'll likely stick with it.

My only complaint is that the CDs take a while to rip. It's either that I have FLAC set to a very high level of compression, and/or that the CD/DVD drive in my computer is just too darned slow. Anyway, I've been eyeing some external drives. Lastly, like you, I'm thinking about a 250GB hard drive for the CD library... When you say you're half through yours, how many albums/songs does that translate to? (I heard 100GB holds about 100 CD albums in FLAC format.)