First Appearance: Strange Tales #180 (June, 1975)
Abilities: Stronger than a normal human being, Gamora is extremely agile and an expert fighter.  She has a wide knowledge of almost every weapon in the galaxy and at times has had enhanced healing abilities. She's sort of a more powerful Black Widow, but with green skin.
Chances she's in the movie: 99%
Lowdown: The last survivor of an alien race, Gamora was adopted and raised by Thanos to become a supreme assassin. She later spurned her father and fought against him which makes her a perfect member for the "Guardians."  She's also been romantically involved with both Adam Warlock and Nova in the comic books which could lead to some interesting drama if its included in the new film.