Help in finding great Jazz thats well recorded

Not having any idea about the style of jazz that you prefer, or what qualifies a recording as 'really' great (i.e. the recording itself, the performance itself, on only a combination of both) I'll restrict my recommendation to a label, Concord Jazz. They are consistently good, often excellent or outstanding. Their artists are slightly off the beaten path, but fine none-the-less. Well worth a try.

My introduction to that label was from a friend who started me off with an LP, 'Just Friends' by the LA 4, which consisted of Laurindo Almedia, Ray Brown, Jeff Hamilton and Bud Shank. When it came out on CD I bought it and was not disappointed with the conversion. This is relatively laid back music and the recording is consonant with the style. It is not necessarily 'demo' stuff (or it is depending on your expectations) but the playing and music will compensate for any shortcomings you might think exist.

Two other recordings of equal quality and potential for enjoyment that I really enjoy feature Charlie Haden on Verve. 'Night and the City' with Kenny Barron and 'Beyond the Missouri Sky" with Pat Metheny. Both are late night jazz.You probably already have them but if not.....

ECM is the best in regard to recording quality.

Alas, those 50s/60s recordings really are excellent (Coltrane's Live at Birdland comes to mind; Ella & Louie...). But ok, here's a couple I like.

Joshua Redman, "Moodswings".

Jazz at the Pawnshop, all 3 volumes. Yes, a live recording.

You are being modest when saying 200 titles is a small library. That's a pretty decent Jazz collection! Here's one to break the mold of the same old same old Jazz recommendations:
Helge Lien Trio, Hello Troll.

Let me hear what you think of that title (c:

Blue Note recordings always sound very, very good. Older recordings are not necessarily inferior, on the contrary, I usually find them to be better.