When I think of elegance in the twohander, I think of very clear unwinding of the body and an evident Kinetic chain, so my vote would probably be Djokovic, but it looks better in slow motion. Soderling also had a pretty smooth two hander.
have to think on this.
agassi, nalbandian and co. have great 2hbhs, but I wouldn't think of them as elegant per se.
honorable mention: Juan Carlos Ferrero
ATP: Topspin is OP. Devs please nerf.
My Tennis: My serve has too much topspin and my forehand not enough.