The best ones depend on your feet. No matter what recommendations you get here, its how they fit your feet that count.
The best suggestion I can give is to go to one of those athletic shoe stores in your local mall and try on various brands. When you find one that feels comfortable on your feet - those are the ones to get.
Do this now, long before you go to WDW, because the second most important suggestion is that you make sure you break them in before you go to WDW.