Metroid is one of the few Nintendo franchises that frequently changes up the villains, so I decided to make a thread to see which villain is the most popular.

Samus' first main villain was the evil Mother Brain. Mother Brain was an AI created by the Chozo, but turned against them when Ridley and the Space Pirates invaded planet Zebes. From then on she acted as the leader of the Space Pirates until her demise at the hands of Samus Aran at the end of Super Metroid.

Ridley is a high-ranking Space Pirate General and the arch-nemesis of Samus Aran. Ridley first met Samus when he raided her home colony K-2L. Ridley was about the kill three-year old Samus before her mother pushed her out of the way. Ridley brutally butchered Samus' parents, but somehow Samus managed to survive. Samus swore revenge on Ridley and finally managed to kill him for good in Super Metroid. The Galactic Federation however took a DNA sample from Ridley and managed to clone him in Metroid: Other M and Metroid Fusion.

After Samus defeated Metroid Prime on Tallon IV, the creature began to destabilize, and in a desperate move it absorbed her Phazon Suit and subsequently exploded. Little did Samus know that a new enemy was born from her DNA and the remains of Metroid Prime, using her Phazon Suit as a mold for her new body - the creature now known as Dark Samus. Dark Samus sought to turn every planet in the universe into a copy of Phaaze, the origin of all Phazon in the universe. Samus finally managed to kill her at the end of Metroid Prime 3 during a final confrontation on planet Phaaze. 

The SA-X is an X-parasite mimicking Samus at full power. After Samus's first encounter with the X on planet SR388, her powersuit was infected by the parasites. The Galactic Federation surgically removed the infected portions of her suit and sent the pieces to the Biologic Space Laboratories Research Station's Quarantine Bay. Once there, the X inside the infected suit parts seemingly combined and transformed into a copy of Samus in her standard Varia Suit. It should be known that the metroids were created by the Chozo to exterminate the X-parasites living on SR388. When Samus killed all the metroids she unknowingly allowed the X-parasites to make a recovery in their population during the events of Metroid Fusion. The X-parasites were exterminated at the end of Metroid Fusion, alongside SR388. 

Sakamoto, the asshole responsible for Metroid: Other M.

Dark Samus, will explain my reasoning after I get back from my next class.

In terms of how good of a villain they were, Metroid Prime/Dark Samus. It was also messing with stuff, and its backstory was interesting. In terms of the my favorite character, SA X. I find Ridley annoying despite him being Samus' personal enemy, and Mother Brain never felt too menacing until you battled her.

Well, I really like Mother Brain and Ridley, but also Dark Samus in Echoes. I'm planning on a ney playthrough of Prime 2.

Metroid doesn't have "villains" it has monsters.

Like the monster in the Alien movies is not evil, he's out to get food and pro-create... humans happen to be a vessel for its eggs :-/

The SA-X.

Also, the asshole who's responsible for Metroid Other M is also responsible for Metroid/Super Metroid/Metroid Fusion/Metroid Zero Mission...

Most of the entries on my list are highly intelligent, that includes Ridley (read the manga) and the SA-X.

Ridley, Mother Brain, Metroid Prime/Dark Samus, and SA X were all sentient beings capable of reason and looking for their own self-interests. If these characters aren't villains than neither are human being villians, becuase all they are looking to do is prosper. None of these characters are like the Xenomorphs from alien. That is a role left to the Metroids. 

Only the stuff you fuck up counts. :p
(I don't like Super Metroid ;x)

Hey, I don't either