You could, nay should, try some Ohio Players. Love Rollercoaster, Skin Tight and Fire.
You could also try Chuck Brown - Bustin' Loose. Then there's the entire Parliament-Funkadelic catalogue: Tear The Roof Off, Red Hot Mama, Supergroovalisticposifunkstication, Flashlight etc.
There's so much more but it depends on what kind of sound you're after. Oh yeah, can't forget Curtis Mayfield. EDIT: D'oh, how can I forget Sly?