September! Decent chance of getting free dining plus you can do MNSSHP. We went last year and the crowds were non-existent. The longest wait time we saw was 20 minutes for Soarin and most of the time the posted wait times were longer than we actually waited. We rode Toy Story one night (not even during EMH) 5 or 6 times in a row. The line was basically as fast as you can walk back through, you're in the little corrals to be loaded on the next or 2nd round of cars. It's hot but not miserable like summer would be plus that makes it great for afternoons at the pool or if you want to do a water park.