I have to agree with TNT, Rors has an amazing move through the ball, smooth yet incredibly fast or beautifully violent. It is a natural move, nothing to mechanical just pick your target and pull the trigger.
Another swing I cannot get enough of Billy Haas's, just a classic swing. (CG's favorite)
King Louis Oosthuizen, after watching him at the Masters how can you not be sold on that swing?
Adam is also up there for the mechanical brilliance of it.
There are pieces of other peoples swings that are quite enjoyable. The way Westy "covers" the ball at impact with his chest. When have you seen this guy come out of a shot? I haven't.