Who is Godzillas Ultimate enemy???

Keizer Ghidorah. He almost killed godzilla, but if the humans didn't save Godzilla. godzilla would have died

what about mechagodzilla 2? he almost killed godzilla as well

^He paralyzed him. Big difference

Keizer is the ultimate foe, godzilla didn't kill desotroyah Super-X3 did, and like High said the Strongest godzilla Almoast died, and FW godzilla is the ultimate godzilla because he deafeted hoard after hoard of monsters in a few days

Paralyzing some one to the point you can combard them endlessly, without them being about to do anything back is pretty much aa death blow, without Rodan's intervention I think it's clear Godzilla would have inevitably died.

Ghidorah or mechagodzilla. Destroyah is the strongest, but unfortunately he's only been in one movie. Ghidorah's been in the most, but I think it's mechagodzilla that puts Godzilla on edge the most.

Godzilla vs mechagodzilla- Destroyed godzilla to the point no other monster in the series managed to

Terror of Mechagodzilla- This was a pretty bleak movie for Godzilla he got destroyed for most of it

Godzilla vs MechaGodzillaII- Godzilla was basically on his deathbed until Rodan went beatmode and gave him the spiral ray while healing him, and melting Mechagodzilla's armor

Godzilla against mechagodzilla- tied not many movies where there's a tie in the end

Tokyo SOS- Somewhat a tie, Godzilla kind of died in this movie as mechagodzilla dragged him into the depths. Questionable death no doubt, but the kiryu didn't really lose.

well its a tie between Mechagodzilla's and ghidorah's

Destroyah=Overrated

the oxygen destroyer 

Yeah, I'd have to say Ghidorah is his ultimate rival. He's not his absolute strongest foe, though he is in that top tier of possible Godzilla-killers, but he is extremely recognizable, and for this reason, he's considered to be Godzilla's main rival throughout the franchise.

Destoroyah. Not only is he his strongest foe, he's also the living incarnation of the Oxygen Destroyer, which is arguably more worthy of the title of Godzilla's true arch-nemesis than Ghidorah. Ghidorah comes second, of course, due to the great number of times he's fought Godzilla and the fact that Keizer Ghidorah is his second most powerful foe.

Its not really who is the strongest foe, Its Godzillas ultimate foe. The one who has pushed him to his limits every time they have faced. And that title goes to MechaGodzilla. From Alien to Human they both have nearly killed the king. Godzillas ultimate foe is mechaG:).

@GORILLAGODZILLA77897 I know that, I said it wasn't just because it was the most powerful, but also because it was the incarnation of the Oxygen Destroyer, which killed the original Godzilla.

I just had an idea: I'll say who was the "ultimate enemy"/arch-nemesis of each individual incarnation of Godzilla.

Godzilla '54: The Oxygen Destroyer/Dr. Serizawa (For obvious reasons.)

Showa Godzilla: King Ghidorah (He was one of this Godzilla's strongest foes and the one he fought the most often.)

Heisei Godzilla: Destoroyah (Since this incarnation never fought any foe in more than one movie, unless you count the various Super Xs, Destoroyah is the obvious choice due to reasons I've already listed. Also, he killed Godzilla Jr., so there's another reason.)

Godzilla 2000: Orga (He's the only monster we ever saw him fight.)

vs. Megaguirus Godzilla: Megaguirus (Same as above.)

GMK Godzilla: Ghidorah (He gave him the best fight by far out of the three guardian monsters.)

KiryuGoji: Kiryu (Duh.)

FW Godzilla: Monster X/Keizer Ghidorah (Since he was the only monster able to match, and, after transforming, defeat him in a fight.)

Legendary Godzilla: The M.U.T.O.s (Once again, they're the only monsters we've seen him fight, not counting the comic, and they're his species' natural enemies.)

ghidorah

heisenberg

Destroyah. He or she has the powers of the oxygen destroyer. 

id go with final wars king gighdorah because he is the only monster that has come even remolty close to killing godzilla.