Dbpoweramp. Best there is. Converting to wav takes up the most room. I prefer ALAC (m4a lossless) to use less space, aiff for archiving. Mp3 blows imho. Unless it's 320 cbr. And that's only for portable use. But I have 500gb iPods for carry around, and 1tb ssd in my vehicle connected to a car pc, that plays every file up to 24/192.