Doubletree is way closer. It is literally across the street from the entrance. Holiday inn is back a little more maybe 1/4 to 1/2 mile. Doubletree has tons of fees (internet, parking etc.) I don't think the Holiday Inn does. I stayed at the Hampton Inn which is about 1/2 mile or so north of the doubletree and it was nice. There is a Quality Inn next to it all well that looked acceptable. These two properties both have free internet/ parking and breakfast included. The hampton had mini fridges, microwave and safe for laptops.
I would take the holiday Inn if it has the amenities you like otherwise consider the holiday inn or quality hotel. They are walking distance from parks and have free shuttles too.