I'm afraid I have three different Dialga's, but no Dialga G.
Dialga (5/127)
Dialga (6/127 Reverse Holo)
Dialga (23/127 Reverse Holo - Colorless Misprint)
Updated with TONS of new stuff from Regionals, I also took down my commons, uncommons, and most trainers because I have too many to keep an updated list.
Looking for 2 Dialga G