The best CD I ever bought is always relative to the moment. I mean I thoroughly enjoyed Jay-Z's Black Album, Outkast's Speakerboxxx/The Love Below, and Toby Lightman's Little Things.

I also liked Bone Thugs n Harmony's E.1999 and Art of War albums. Usher's Confession [Special Edition] is nice too as well as Alicia Keys' Diary of Alicia Keys (Bonus Disc) album. I can't say for sure now, but eh. I do like American Idiot by Green Day, but eh.

I honestly don't know. If I had to ultimately pick, I'd go with Speakerboxxx/The Love Below.