De La Soul's '3 Feet High and Rising' has a good selection of clean tracks and fun for you:
Change in Speak
Potholes in my Lawn
Say No Go (obvious drug references here but is against drug use)
The Magic Number
This is a Recording for Living in a Fulltime Era (L.I.F.E)
**EDIT** De La Soul's 'Stakes Is High' album has no clean tracks - didn't think it was worth making a post about it just to say that!
**EDIT** De La Soul's 'De La Soul Is Dead' doesn't contain much cleaness either - it's really only 'Shwingalokate' which is entirely clean.