Girafarig (Hells yeah!) in the original Gold version.
Since then I trained up 13 legitimate level 100s:
On Sapphire
Blaziken (Lost)
Rayquaza (Lost)
Kyogre (Never use - Possibly Lost)
Espeon (Possibly Lost
Umbreon (Possibly Lost)
Metagross
On Platinum
Ursaring
Mismagius
Raichu
Armaldo
Scizor
Garchomp
Gyarados
Arceus
My ones from Sapphire were all on my Pearl version (apart from Blaziken and Rayquaza that I had already lost from glitching) which I can't find
but my Metagross I used to try out the cloning glitch so I still have one on Emerald.
Arceus arrived from an event at lv. 100.