Mpittman is very right to suggest Guru Jazzmatazz 1 and 2, those are great collections for what you are looking for.
If you enjoy that then you could check out Guru's main thing which is Gangstarr, anything from the early 90s is good.
Digable Planets are a great example of jazz rap, their debut is the only album of theirs I have and it is called Reachin' (A New Refutation of Time and Space). This is a very smooth album and one which I highly suggest.
A Tribe Called Quest is very similar to Digable Planets in some respects, but better lyrically. The Low End Theory is a typical starting place for them. I'd consider this to be the starting place for jazz rap in general.
The Roots and Common are some other, more recent, examples of what you are describing.
If you want more information and a list of more albums to check out then I would suggest
http://www.allmusic.com/cg/amg.dll?p...81&sql=77:2920
But check out Jazzmatazz, The Low End Theory, and Reachin'. I think you'll find what you are looking for.