Here is my starter list for jazz cds - some of which have already been mentioned:
Louis Armstrong - "Hot Fives and Sevens" (JSP) 4 cd box set available for about $25.00 - absolutely essential classic jazz
Art Blakey and the Jazz Messengers - "Moanin'" (Blue Note)
Clifford Brown - "Clifford Brown and Max Roach" (Verve/Emarcy)
Ornette Coleman - "The Shape of Jazz to Come" (Atlantic) - seminal free jazz session
John Coltrane - "Blue Train" (Blue Note), "Giant Steps"(Atlantic), "A Love Supreme" (Impulse)
Chick Corea - "Now He Sings, Now He Sobs" (Blue Note/UA)
Miles Davis - "Relaxin" (Fantasy/Original Jazz Classics), "Kind of Blue" (Columbia), "Miles Smiles" (Columbia)
Duke Ellington - "The Blanton Webster Band" (RCA) a 3 cd set of material by the band generally acknowledge to be Ellington's best
Bill Evans - "Sunday at the Village Vanguard" (Fantasy/OJC), "Waltz for Debby" (Fantasy/OJC) - these two discs, recorded live at New York's Village Vanguard set the standard for the piano, bass, drums jazz trio
Dexter Gordon - "Go" (Blue Note) or "A Swingin' Affair" (Blue Note)
Herbie Hancock - "Maiden Vogage" (Blue Note)
Charles Mingus - "Mingus Ah um" (Columbia), "Blues and Roots" (Rhino/Atlantic)
Hank Mobley - "Soul Station" (Blue Note)
Thelonious Monk - "Genius of Modern Music Vol.s I & II" (Blue Note), "Brilliant Corners" (Fantasy/OJC), "Monk's Music" (Fantasy/OJC)
Wes Montgomery - "Incredible Jazz Guitar" (Fantasy/OJC)
Lee Morgan - "The Sidewinder" (Blue Note)
Oliver Nelson - "The Blues and the Abstract Truth" (Impulse)
Charlie Parker - "Yardbird Suite: The Ultimate Charlie Parker Collection" (Rhino) - This 2 cd compilation is the perfect introduction to Charlie Parker containing most of his essential performances for both the Dial and Savoy labels as well as some rare live radio broadcasts - includes a deluxe booklet with great biographical and discographical information and cool pics.
Art Pepper - "Meets the Rhythm Section" (Fantasy/OJC)
Oscar Peterson - "Night Train" (Verve"
Bud Powell - "The Amazing Bud Powell Vol.s I & II" (Blue Note)
Sonny Rollins - "Saxophone Colossus" (Fantasy/OJC), "A Night at the Village Vanguard" (Fantasy/OJC)
Wayne Shorter - "Speak No Evil" (Blue Note), "Ju Ju" (Blue Note)
Horace Silver - "Song for My Father" (Blue Note)
There is so much good jazz out there - I had to leave out a lot of excellent, exellent music. Nonetheless, I think this is a pretty good starting list - although it is a bit heavy on Blue Note albums from 1955-65 (my favorite era in jazz).
P.S. - I intentionally left out more "out" or avant-garde sessions (other than the Ornette Coleman) but if you develop a taste for more out jazz you should start with Blue Note albums like Andrew Hill's "Point of Departure" and Eric Dolphy's "Out to Lunch" and work your way up to artists like Albert Ayler and Cecil Taylor.