I vote for Wawrinka for following reasons:
the fluidity(Fed is amazing fluid too)
racquet drop(no time racquet hitting face is pointing up, Sampras and Federer's racquet hitting face has time of pointing slightly up during racquet drop)
I found there are two kinds of racquet drops, Sampras, Federer is one kind
Pancho and Wawrinka is another kind, their racquet drop forms a plane which is perpendicular to their body.
I am still looking for serves similar to Pancho.
radical mp x 7, 344sw/353w,7ptsHL. prince/wilson natural gut. volkl polys.