your favorite 3 Duke Ellington albums?

MasterpiecesThis One's For BlantonDuke's Big 4

I'd add Money Jungle with Mingus and Roach. Wild and hard-hitting.

I'm not a big jazz fan, but enjoy the earlier Ellington stuff. Specifically these 2 cd's:

Swing Legends - 24 Classic Hits, Robert Parker series. 1920's to 1940.

Sophisticated Lady, Victor Jazz, 1940-46.

Both have excellent sound for the time period.

Ella at Duke's Place
Blues in Orbit
Never No Lament: The Blanton-Webster Band

It's not "technically" Duke... but since you already like "Side by Side", you should hear "Johnny Hodges with Billy Strayhorn's Orchestra.  It's one of my all-time favorites regardless of genre.  I see where it is available on a 2013 SACD release.  That should really be special!