Help me build up a jazz album collection. Can you suggest a must have album?

I've enjoyed this discussion of artists, labels and specific albums and can't quibble with most of it, but unless I missed it, there's scant mention of Duke Ellington's big band work on Columbia (Blues in Orbit, Jazz Party, Indigos and others) or his later small ensemble work on Pablo. The Duke's earlier work is also magnificent too but, as others pointed out, is best enjoyed with a dedicated mono phono cartridge. Also, MPS issued some excellent sounding records in Europe. 

Big Band Basie by the Depaul University Jazz Ensemble with some renowned guests such as Count Basie and Quincy Jones. The performance is above average for a college band, but what made me sit up and take notice was the production. When I checked the liner notes, it was recorded by Keith Johnson of Reference Recordings fame. The music is performed without significant flaws and it is enjoyable, but the recording is superb.

Let's not forget The Dave Pell Octet !  I know that the sound of an octet might not be everyone's "Cup O' Tea" but Dave had a handle on a totally unique sound.  My absolute favorite of his was his arrangement of "Mountain Greenery".  Check it out ----- you won't regret it !     [We ALL say that !]

I’m assuming you will listen a bit on YouTube before buying someone we recommend, because something like Miles Davis, Bitches Brew is important, but not the 1st Miles Davis you should experience, that is after you know more about him and his music. He went thru several stages, his personality, there is no way he could play the same stuff over and over again, ......

i.e. Toot’s Thielemans is a Harmonica Player with a unique sound, this would be a good start

Toots, Live 3

Elliottnewcombjr - yes I have been listening on YouTube and also various streaming services. To date, for anyone interested, my total purchases have equaled $937 on eBay, discogs and Amazon. I am very happy with everyone sharing their choices. I don’t really want to say what I have chosen because honestly it’s all over the place. I am thinking about starting a blues album thread, but my wallet is getting thin….