Ok, so I've been giving GGX a look. Unfortunately I haven't been able to find much information on it, at least not nearly as much as Beckmann's.
I gather this is the correct normalized version?
Currently I've only evaluated the Blinn-Phong NDF, Beckmann and what I think is the correct GGX NDF. One thing that I noticed right away is that Blinn-Phong and Beckmann are nearly identical for roughness values below 0.3 or so. From 0.3 to 0.5 they are still pretty similar. GGX on the other hand is substantially different across the board, and that was with the Cook-Torrance G function. Next I tried your BRDF and the differences grew even further. I'm not sure which is more physically correct, but to my eyes I think I might prefer Beckmann + Cook-Torrance.
Here is a graph of theta H for a roughness of about 1.2:
Blue is Beckmann and C-T G. Red is GGX and C-T G. Green is your BRDF.