I went to Arizona Grill in Islamabad twice and both times it was a great and delicious experience. So I'd definitely recommend every Islamabad visitor to give it a try.
Cuisine: Grill/Tex-Mex ::: Location: Laila Market F-7 ::: Price range: Rs.250+ per head ::: Serves continental fare as well as grills. Reasonably popular restaurant with good service and pleasing décor. (Fairly Expensive)
My Favourite is grilled chiken with lemon juice dipper..very tasty......