Comedy CDs are an iffy recommendation.  What's funny today might bore you tomorrow.  Some jokes are only funny the first time.  Jim Gaffigan's CD, "Doin' My Time," scores high on the replay factor.  Perhaps it's his delivery (dry self-deprecation with a twist of smug).  Perhaps it's his avant-garde style of humor (he spends about a quarter of the time pretending to be a critical female member of his own show, weaving "her" comments with his).  Perhaps it's just his voice, which has a malleable whine to it that never gets annoying and which makes his self-mockery seem humorously authentic instead of just patronizing or pathetic.