My favorite era in music is the early-to-mid 70's. It was the time when funk started to influence soul artists, but before things got too disco. This soul/funk style birthed countless classics, including an album that I've already posted here, Marvin Gaye's, "What's Going On."
I don't think any artist personifies this era like Curtis Mayfield does. Mayfield moved on from The Impressions and went solo with his incredible vocal ability and a band who's compositions featured heavy percussions and brass arrangements.
Though Mayfield had solo albums that did better commercially and critically, my recommendation is 1970's "Curtis." I think this album encompasses Mayfield's style above all others, and is a personal classic of mine.
Standout tracks include, "Move On Up," "If There's Hell Below," "We The People Who Are Darker Than Blue," and "The Makings Of You," which you might recognize sampled in "The Joy," by Jay-Z & Kanye West.