Hyatt Place is just south of the Anaheim Convention Center and is right in front of the Cortona Inn & Suites. It is walkable, but driving or taking the Anaheim Resort Transportation bus might work out better.
The Cortona Inn is southeast of the Anaheim Convention Center, between the Clarion Hotel and the new Hyatt Place (currently under construction). It’s also across the street from the Toy Story Parking Lot. In my opinion, it’s on the outside edge of walking distance, however there is an Anaheim Resort Transportation stop nearby.
La Quinta Inn is located on the east side of Clementine Street just north of Katella, right behind the Anaheim GardenWalk. The walk is not too bad, but if you had young children I might suggest driving or taking the Anaheim Resort Transportation that picks up right next door.