I asked the same question almost 6 months ago since I have a 3802 as well. I went with Klipsch Reference series since they are extrememly efficient, and sound very warm on the Denon. I find it to be a remarkable combination and easy on the wallet. Of course I have dual SVS 20-39CS+'s for the low end.
This setup sounds GREAT with my 3801. Very warm and natural and at a modest price. Some of the speakers that I remember hearing match well with the Dennon are Polks, Energy, and Atlantic Technology. I am sure there are others.
I have just recently upgraded to a 3802 from the 2802. I have Paradigm Reference Studio/20s and Studio CC up front. Due to room layout,I have Def Tech BP2x in rear. They all sound great together. Hopefully my 25-31pci will ship soon to complete the setup.