There are several restaurants on property that offer outdoor seating (I also like sitting outdoors because most outdoor restaurants in Disney have scenic lakes nearby).
There are great choices at DTD:
I
believe that Bongo's, Paradiso 37, House of Blues, Portobello and WP Cafe all have outdoor seating, as well as Earl of Sandwich as a QS. Also, if QS sounds better, you could always take out food and sit outside. There are plenty of well-spaced out seating areas in DTD.
Some other choices in the parks off the top of my head are:
MK-Casey's, Peco's, Tortuga and Cosmic's. I also found Crystal Palace to be a nice place to go. Tables are nicely spread out and before your name is called you sit on the outdoor porch with a great view of the castle.
Epcot-Most QS, along with La Hacienda, I believe, and Rose & Crown
HS-Brown Derby as TS, unfortunately in this park, as much as I love the food, there aren't many outdoor seating areas, except for Toy Story Pizza Planet
AK-Yak and Yeti QS, Flame Tree, Rest. and Pizzafari
Resorts-ESPN Club, Kouzzina and Narcoosee's
Hope I helped!!

Have fun!