Tim Marques: Excellent view from the top of the castle. Try and get on a guided tour they are free and help you understand a lot about the castle and Edignburgh.
Francesco de Virgilio: Wonderful collection, tons of Italian Renaissance paintings. Don't miss Leonardo da Vinci and try to get the small tables near the window at the café at the gardens level, the park view is relaxing.
Adam M: Probably the best view in Edinburgh. Central location and 287 stairs up gives you a view of pretty much everything. Well worth going all the way to the top. Be prepared for narrow circular staircases
Amaury J: Beautiful gardens on the side of the Edinburgh Castle. Great for a stroll, a nap, or a picnic. Beautiful and peaceful area in the middle of the city.