Kirlia> Male> Gallade
Kirlia>Femae>Gardevoir
You forgot:
Weavile
Magnezone
Lickilicky
Yanmega
Leafeon
Glaceon
Gliscor
Probopass
Dusknoir
Frosslass
Admittedly, the only ones worth mentioning from those are Weavile, Yanmega, Leafeon, Gliscor, Dusknoir, and Frosslass.
No:
Male Kirlia + Dawn Stone --> Gallade
Either Gender Kirlia Lv.30 --> Gardevoir
You can still get Male Gardevoirs and Female Glalies, you know.
I hatched a Modest Male Ralts, So I made it Gardevoir, and Modest is a stupid nature for Gallade :/
I'd vote for Yanmega or Tangrowth if either were options
YOU BOTH FORGOT TANGROWTH! D: