For Dylan I'd go with Bringing it All Back Home, Hiway 61 and Blonde on Blonde.
Greatest threepeat ever?
And I second a whole bunch of the other ones listed above, especially The Smiths and Talking Heads.
I'm not sick of CCR yet: Green River, Willy and the Poor Boys, Cosmo's Factory
Tom Waits: Swordgiraffetrombones, Rain Dogs, Franks Wild Years
Sonic Youth: EVOL, Sister, Daydream Nation
Built to Spill: Ultimate Alternative Wavers, There's Nothing Wrong with Love, Perfect from Now On
OutKast: ATliens, Aquemini, Stankonia
Nick Cave: Your Funeral... My Trial, Tender Prey, The Good Son (For Nick Cave, you could really start with any album up through Let Love In and the next two are great, those are just the strongest to me.)
Marvin Gaye: What's Going On, Let's Get It On, I Want You (I just double checked it, and apparently Trouble Man comes after What's Going On, but it's not fair to include soundtracks, is it?)
Neil Young is tough because I don't love all of Harvest, and is Zuma really a great album? I don't know if I've listened to the whole thing. Unless live albums count? I don't see why not as long as it's considered canonical: Time Fades Away, On the Beach, Tonight's the Night
Charles Mingus: Tijuana Moods, The Black Saint and the Sinner Lady, Mingus Mingus Mingus Mingus Mingus (He has so many albums, I checked Wikipedia for chronology, and there's also Blues & Roots, Mingus Ah Um and Mingus Dynasty, and probably a few other threepeats, those are just the six I know best.)
Edit: Forgot the first one that came to mind: Funkadelic, Free Your Mind... And Your Ass Will Follow, Maggot Brain