We did 11 nights deluxe in Jan '08 and we're doing 9 nights deluxe on our next trip in Sept.
Take advantage of the 2 credit meals! We did Narcoosees, California Grill, Artist Point, Yachtsman, and CRT on our last trip, plus ordered room service twice. After Sept, we'll be able to say we've tried every signature restaurant at Disney.
Also, take a look at the snack sticky on the top of the board and make a mental note of some of the more interesting options. There is such a great variety, and with the extra snacks on the deluxe plan you can try a lot of them!
ETA: A few must eats, in my opinion - Teppan Edo at Epcot, Tutto Italia at Epcot, Kona Cafe at the Polynesian, California Grill at the Contemporary (especially if you can get a reservation close to MK fireworks time), Narcoosees at the Grand Floridian.