Another cool list I stumbled upon is The New Yorker's list of 100 Essential Jazz Albums. There are other lists of this type (see WBGO), but it's always interesting to see new lists and what is included and what is not. I'm still trying to figure out how The New Yorker's list organized. It's certainly not ranked (given the high numbers next to Brubeck's Time Out, Coltrane's A Love Supreme, and Miles Davis's The Birth of the Cool).
My Amazon wish list just got a bit longer. :)