At the risk of sounding like Gary Player, I enjoy each of them almost equally (and I think Shivas really has a point about the PGA, despite the predictably contrarian nature of his choice).
Isn't this exactly what we want from our four majors -- four flavors, not four versions of the same flavor (flavour)? I would enjoy the PGA even more if it truly became the bizarro U.S. Open (great course, soft greens, light rough, reasonable length, par left at 72, low, low scores), but right now we've got four distinct majors that ought to try very hard to become even more distinct from each other.