Adventureland
Sadly, in the grand scheme of things we cannot forget that Adventureland has lost a lot to get what we have now - it has lost the valuable space of Jungle Cruise, and a icon that forever will not appear in the parks for now. What that means is that Adventureland requires the necessary updates that keeps it not only big enough but relevant to the modern Disney Parks.
The main problem with Adventureland is that it lacks a cohesive theme- there's Agrabah in some places, tiki, and suddenly Carribean/Spanish theming. While some fans argue that this is able to immanent pure "Adventure" instead of a place like Fantasyland or Frontierland, it's still very messy and glaringly ugly compared to the other parks- especially with the Magic Carpets Ride (There are literally five other rides of the same ride type in WDW).