Girlfriends. Gal pals. Sidekicks. Whatever you call them, superheroes just wouldn't be able to rise to their full powers without a love interest — and usually a healthy dose of some smoldering on-screen sexuality.
So whether it's the famous upside down kiss between Tobey Maguire's Spider-Man and girlfriend Kirsten Dunst or Gwyneth Paltrow's slinky skirts and witty banter with Iron Man Robert Downey, Jr., the chemistry between a superhero and his civilian paramour is usually an integral part of the story.
With Spidey, Batman and their respective girlfriends poised for domination at the summer box office, we take a look at the women who have stood behind their supermen — and rate them on their brains, beauty, bravery and butt-kicking.
15. Maggie Gyllenhaal
In "The Dark Knight" (2008), Gyllenhaal takes over the role of Rachel Dawes played previously by Katie Holmes. Here, Bruce Wayne suffers through her lovers' quandary: she promises him that they'll be together if and when he gives up being Batman, before sharing a kiss. But ultimately, she decides to marry her boss, District Attorney Harvey Dent. It never happens because, gulp, she dies as the result of a nefarious Joker plot.
Brains: 4
Bravery: 2
Butt-Kicking: 0
Beauty: 3
Total Score: 9
14. Kirsten Dunst
Appearing as Mary Jane Watson in three "Spider-Man" films opposite Tobey Maguire, Dunst plays Peter Parker's next-door neighbor and classmate, on whom he has a crush. While taking pictures of her for the school newspaper, a spider bites him and he begins developing his superpowers — one of which later manifests itself in kissing her upside down.
Brains: 4
Bravery: 2
Butt-Kicking: 0
Beauty: 3
Total Score: 9
13. Margot Kidder
It's a bird, it's a plane, it's Lois Lane, Superman's reporter girlfriend in the three Christopher Reeve classics. They both work at Metropolis' Daily Planet, where Lois first views Clark as a sort of country bumpkin — until his alter ego saves her from a helicopter crash. Then, the caped man takes her on a flight over the city, she christens him "Superman," making him a celebrity and the love of her life.
Brains: 5
Bravery: 3
Butt-Kicking: 0
Beauty: 4
Total Score: 12
12. Nicole Kidman
Back in the day when she was Tom Cruise's wife, and Val Kilmer played Batman, Kidman starred as Dr. Chase Meridian, a psychiatrist, in 1995's "Batman Forever." Their first date is at a charity circus event where all hell breaks loose with Two-Face and his henchmen. Later, Batman rescues Chase — and Robin — from falling to their deaths and Chase discovers Batman's real identity.
Brains: 5
Bravery: 3
Butt-Kicking: 0
Beauty: 5
Total Score: 13
11. Liv Tyler
In "The Incredible Hulk" (2008), she takes over the role as Dr. Betty Ross, the love interest of Dr. Bruce Banner (Edward Norton), you know, the one who blows up and goes green when he's angry. She's Banner's coworker in the science lab run by her father, researching gamma radiation to increase healing time in soldiers — before he destroys it and escapes. Later, the Hulk unexpectedly returns and rescues her in a helicopter assault and she tries to curb his angry impulses.
Brains: 5
Bravery: 3
Butt-Kicking: 0
Beauty: 5
Total Score: 13
10. Jennifer Connelly
As Betty Ross in 2003's "Hulk," opposite Eric Bana as Bruce Banner/The Hulk, she had broken up with her fellow researcher because he was too withdrawn emotionally. But events (a job offer, an experiment that goes horribly awry) conspire to bring them together, and she witnesses his transformation into the green-hued monster, although in the end, they do not end up together.
Brains: 5
Bravery: 3
Butt-Kicking: 0
Beauty: 5
Total Score: 13
9. Gwyneth Paltrow
She's Pepper Potts, assistant and love interest of billionaire businessman Tony Stark, a.k.a. Iron Man, now shooting a third installment. Their employer/employee relationship often gets thrown out the window, but never gets graphic. She becomes CEO of Stark Industries in 2010's "Iron Man 2," but later resigns, and finally shows her affection in the form of a kiss.
Brains: 5
Bravery: 3
Butt-Kicking: 1
Beauty: 5
Total Score: 14
8. Eva Mendes
In 2007's "Ghost Rider," she plays Roxanne Simpson, the childhood sweetheart of Johnny Blaze (Nicolas Cage), whom he later meets when she's a television news reporter, but their romance is not nearly as flaming hot as his head. You might say it bombed, just like the film did.
Brains: 5
Bravery: 2
Butt-Kicking: 3
Beauty: 5
Total Score: 15
7. Katie Holmes
As Rachel Dawes in 2005's "Batman Begins," she's the assistant district attorney who takes Bruce Wayne (Christian Bale) to the parole hearing of an arch nemesis, Joe Chill, who murdered Bruce's parents. Rachel lectures him on the difference between justice and revenge, slaps him, apologizes, gets her butt rescued by Batman numerous times ... and eventually figures out her savior is really Bruce Wayne.
Brains: 4
Bravery: 3
Butt-Kicking: 4
Beauty: 4
Total Score: 15
6. Selma Blair
As Liz Sherman in 2004's "Hellboy" (and its 2008 sequel), she has volatile pyrokinetic abilities and becomes romantically attached to Hellboy (Ron Perlman) when he visits her in a mental hospital. They are both part of the Bureau of Paranormal Research and Defense. Per superhero protocol, he saves her from near death and they share a kiss.
Brains: 5
Bravery: 4
Butt-Kicking: 3
Beauty: 4
Total Score: 16
5. Natalie Portman
The Oscar-winning actress also won the heart of the hammer-throwing Thor (Chris Hemsworth) in last year's blockbuster, playing astrophysicist Jane Foster. She finds her Norse warrior god in the New Mexico desert and they develop a romance even as he battles against his brother Loki. But with Thor eventually returned to Asgard, it makes for a very long distance relationship.
Brains: 5
Bravery: 4
Butt-Kicking: 4
Beauty: 5
Total Score: 18
4. Emma Stone
We've seen Gwen Stacy before, played by Bryce Dallas Howard in 2007's "Spider-Man 3." As Peter Parker's high school sweetheart -- no, Peter Parker's other high school sweetheart -- in reboot "The Amazing Spider-Man," Stone takes on the role of the junior scientist and daughter of NYPD Captain George Stacy. Stone's Gwen is a far cry from Howard's damsel-in-distress; when Spider-Man needs an antidote to a super-villain's diabolical bio-warfare, Gwen puts herself in mortal danger to help him out.
Brains: 5
Bravery: 5
Butt-Kicking: 3
Beauty: 5
Total Score: 18
3. Kate Bosworth
She's Lois Lane to Brandon Routh's Clark Kent in the 2006 movie "Superman Returns," in which the Man of Steel comes back to Earth and fights to regain her love. It's been five years and she's moved on, winning a Pulitzer Prize for her Daily Planet article, "Why the World Doesn't Need Superman." Ah, but it does, and in the end, so does she. And he needs her: At one point, Lois rescues him from the ocean.
Brains: 5
Bravery: 5
Butt-Kicking: 4
Beauty: 5
Total Score: 19
2. Hayley Atwell
As Peggy Carter in last year's "Captain America: The First Avenger," she's a World War II British military officer who meets Steve Rogers (Captain America himself) during his basic training, then joins him on his mission against the Nazis and Red Skull, at one point killing a German spy. All that fighting leads to flirtation ... and kissing ... but she's left behind when he's frozen for 70 years.
Brains: 5
Bravery: 5
Butt-Kicking: 5
Beauty: 4
Total Score: 19
1. Blake Lively
Paired with Ryan Reynolds as Hal Jordan/Green Lantern, Lively plays fellow test pilot (and love interest) Carol Ferris with nearly an equal amount of derring-do, who recognizes Hal as the Green Lantern under his flight suit and mask. Lively did her own aerial stunts, trained by acrobats from Cirque du Soleil.
Brains: 5
Bravery: 5
Butt-Kicking: 5
Beauty: 5
Total Score: 20