Thrown, as in the Messygirl production "Mrs. Bee's Messy Humbling's" last pie hits (with side view) are awesome.
Pushed in faces, as in Dorothy Appleby in Stooge's "In the Sweet Pie and Pie"= also awesome.
I think the excitement factor is an out-of-the-blue pie thrown, but there's also something about the slow burn of a smushed pie that can be equally pleasing.
It's both, no doubt about it. Neither one nor the other is supreme. The ballistic drama of the exploding hurled projectile as it bursts over the face of its unsuspecting target is a beautiful thing, but it does not outmatch the controlled humiliation and gloating relish dealt by the deliberate push, twist and smoosh of the placed pastry.
Have to be pushed. With thrown it may or may not hit the mark and you can't really control where it goes. With a pushed pie, you can slide the contents up or down and determine where to push the contents. A thrown pie you can see it coming and prepare for the shock. A pushed pie, you can surprise the person.