Free Dining for sure. We always go for about 2 weeks and you can get up to 14 days on the free dining promotion and it is also the best deal there is @ Disney.
I think 7 at a deluxe. 7 is just the right amount of days for me. I think if i spent too much time at once I might get tired and cranky and ruin my own magic!
WYR do Disney at Christmastime or summer?