Hmm....
songs:
The Temptations - I Can't Get Next to You
The Temptations - I Wish It Would Rain
The Temptations - Get Ready
The Temptations - I'm Losin' You
Marvin Gaye - What's Goin' On
Gladys Knight and the Pips - My Imagination
Gladys Knight and the Pips - Midnight Train to Georgia
Smokey Robinson and the Miracles - Just My Imagination
Smokey Robinson and the Miracles - Tears of a Clown
The Four Tops - Bernadette
The Four Tops - California Dreamin' (if you can find it, it's very much worth it.)
Stevie Wonder - Supersticious
Stevie Wonder - Livin' for the City
Also, check out Martha Reeves and the Vandellas, and, of course, The Supremes.
For albums, I mostly go greatest hits with this stuff. It's about the only thing with which I do that. Marvin Gaye 'What's Goin' on' is a great album. It's got a strong message against the Vietnam War and it's dripping with soul. Die hard Stevie Wonder fans tend to suggest anything from the 70s. I've got a two disc anthology of sorts of The Temptations and about half the songs suck and the other half are awesome. I bought a best of tape by the Four Tops a bunch of years ago which has that version of California Dreamin' which is, I think, the best example of the Detroit sound out there. I can't find it anywhere else, though.
Also, I've got to suggest Curtis Mayfield. I'll pick one song and it's called 'People Get Ready.' I'll suggest one album and it's simply called 'Curtis.'
Bravo for your interest.