Premium would be the best, also the most expensive, but its Disney and to us, worth it. They are generally the biggest, most paved area on each site. Next choice (for a 35' trailer would be the Full hookup sites, further away from some of the amenities but generally fairly large sites.
Our my choice would be the Preferred loops, closest to boat docks, but they are generally smaller sites. One time we felt a little crowed with a 19' HTT and van, Just able to get the 30'MH on it along with the car, another site we've had was huge. Some of h
the sites in the preferred loops (especially inside sites) could be a challenge to get in.
If you can't site in the loop you request, take whatever you can get, after you get parked and start enjoying Disney (even Fort Wilderness Campground), you will enjoy it.
Ken
2006 Winnebago Outlook 29B E-450.
2012 Honda CR-V AWD
Blue Ox Aventa LX tow bar and Brake Buddy Vantage.