My ten in no order:
Otis Redding - Otis Blue: Otis Redding Sings Soul
Aretha Franklin - I Never Loved a Man the Way I Love You
The Impressions - This is My Country
Wilson Pickett - The Exciting Wilson Pickett
Four Tops - Reach Out
Isaac Hayes - Hot Buttered Soul
Curtis Mayfield - Curtis
Al Green - Let's Stay Together
Sam Cooke - Live at the Harlem Square Club 1963
James Carr - You Got My Mind Messed Up
I've also done a Soul intro compilation
here if you're interested.