What Jazz Records Would You Reccommend?

zmotula asks: "What Jazz records do you think are a must-have for a Jazz Geek? I've got about twenty records I really love (Kind of Blue by Miles Davis, Tijuana Moods by Charlie Mingus, Lush Life by John Coltrane, just to mention some) and I want to spend some more money on buying more. Alas, I can only afford buying around two CDs a month. What records do you think are essential?"