WHO IS GODZILLA'S ULTIMARE FOE?

The reason I have this posted here is because of several movie discussions, and this is about the movies in general. By those lines, this fits better in Classic Godzilla than Godzilla Videos Games or Godzilla Fan Works.

During my time before I joined this site, I snooped about, poking around, finding out what everyone thinks. I have now come to want to know more in depth an answer of which I cannot come to.

WHO truly is Godzilla's ultimate foe?

I have concluded it must be one of the following:

Mothra [she has defeated him the most. She is also extremely intelligent and incredibly fast] (she is frail)
King Gidorah [he has fought him the most. Also, he is consider the main antagonist of Godzilla] (usually under mind control)
Destoroyah [it took about 9 red "spiral rays" directly without major, or minor, damage. These usually kill kaiju instantly] (has to break apart and then fuse again to heal)
MechaGodzilla 1/2/3 [it always has an expansive array of weaponry more than capable of harming Godzilla] (robot)

-MY OPINION-
No one is worthy of this title.
Mothra has defeated Godzilla the most, but has died or had help nearly every time.
MechaGodzilla 1/2/3 have only truly been successful in suppressing Godzilla, and only MechaGodzilla 2 (as Super MechaGodzilla) was able to kill him.
King Gidorah has fought Godzilla the most, but has had the least amount of success. Everytime he just comes back to fight again.
Destoroyah proved to be durable. Extremely durable, but that was virtually it. He killed Jr., but not Godzilla. Also, he attempted to flee. Cowardice is pretty unacceptable. Even King Gidorah fought to the death.

Note1: The reason I say MechaGodzilla 1/2/3 is because they are all essentially/basically the same machine, however they are built with minor changes in abilities and weaknesses by different people.
Note2: Please refrain from mentioning Bagan, Keizer Gidorah and SpaceGodzilla (and Orga). They are not in the above list for a reason.
Note3: Destoroyah's death at the hands of the JSDF does not factor into whether or not he can hold this title. The humans just got lucky. Very lucky.
Bagan: He has appeared only in [a] video-game(s). This is about the movies.
Keizer Gidorah: He is a seperate entity from King Gidorah, evidenced by his copyright icon and the existence of several other Gidorah creatures, mostly in Mothra movies.
SpaceGodzilla: He relies on crystal structures for power and without them, he is a potatoe.
Orga: It looks like a mentally disabled, reptilian gorilla with a turtle shell. It barely put up any kind of fight whatesoever against Godzilla (even SpaceGodzilla did more), and therefor has no right to any title except mentally disabled reptilian gorilla with a turtle shell.

I would like to hear everyone else's thoughts on the kaiju I have listed about. Please refrain from mentioning other kaiju, unless it is Godzilla himself or any form of his son.