The week before and the week after Easter are always the most crowded in Spring, however, Spring Breaks are spread out through March and April. We also get the 2 weeks around Christmas and New Years. Some folks in the Northeast also have a "Winter Break" in February, but this is not the norm. I don't know of anyplace in the midwest or the south that gets that kind if break. If you truly can go anytime you want, go when it is cold and avoid any US holiday, no matter how small. Do keep in mind though that many people have no problem taking their kids out of school, so you will see families any time you go. I personally think people on these boards spend way too much time worrying about how crowds will be when they go. If there were lots of "low crowd" times Disney would be in big trouble money wise. Just plan out your days, use fast pass, and go with the flow. If standing in line will ruin someones trip, maybe WDW is not the place for them.JMHO.