I won't pretend to know enough about jazz to know which albums are essential, but back in the late seventies when I was putting together my first nice audio system the following three direct to disk albums really got me into jazz.
L.A. Four, "Going Home" (Nautilus). Absolutely wonderful! The flute solo in Django (I think) is what sold me on my first real speakers, DCM Time Window.
Bill Berry Band, "For Duke" (M&K RealTime Records). This is a Duke Ellington tribute record by members of his band.
Earl "Fatha" Hines, "Fatha" (M&K RealTime Records). Fatha plays other composer's music.
The last two are still available on one gold CD. Both are well recorded and I highly recommend it.