I've done 2 special tours. Just did Keys to the Kingdom in Sept and it was really awesome but a long day. It's a 5 hour tour and does include lunch. If you do this, prepare to stand a lot with lots of walking. It was very interesting and even for a Disney veteran, there is something to learn.
I've also done the Behind the Seeds tour in the Land in Epcot. This is also a fun (and inexpensive) special tour. Takes about 2 hours if I remember correctly. You go behind the scenes of the area. Very science-y (is that a word?) but interesting.
You can also do a FREE culinary tour close to dinner time at Animal Kingdom lodge. In Jambo house you can tour Boma/Jinko and there is another one at Kindani villiage's Sanna.
Have fun!