Contributed by Suzanne Baldwin, Catalogs.com Top 10 Guru

Sci-fi action has been a staple of summer movies for decades.

The actual definition is somewhat fuzzy, but all sci-fi action stories share two common bonds: A futuristic setting and lots of explosions. If you have a bad guy with unlimited artillery at his disposal and a nefarious plan for your city, call on any one of these fine individuals to give you a hand. They’ll single-handedly (sometimes literally) save the day.

Here are the top ten science fiction action characters:

10. Optimus Prime (Transformers franchise)

He’s a robot. He’s a truck. He’s…an Autobot? Optimus Prime’s origins look a bit silly on paper (survivor of some epic, robot-vs-robot war that decimated a planet of robots? And we’re letting him come to our planet?). Commanding, intense and always on the side of good, this robot, with the other Transformers, will make quick work of any bad guy that comes his way.

9. RoboCop (RoboCop, et. al.)

The second robotic hero on this list, RoboCop’s human background separates him from the rest of the mechanical lawmakers of the future. From a distance, RoboCop almost resembles a classic knight – clad in silver armor, he stomps through Detroit, taking out criminals and wrestling with memories of the man he used to be. He handles corrupt cops, corrupt businesses and mercenaries throughout the trilogy.

8. Wikus van de Merwe (District 9)

Wilkus doesn’t start out as an action hero; he’s a paper pusher that likes to make little gifts for his wife. While investigating District 9 – an alien settlement in Johannesburg – Wilkus is infected with alien DNA, which kicks off his transformation from human into a decapod crustacean…and paper pusher into action hero. Fighting aliens, soldiers, warlords and his own prejudices, Wilkus proved you don’t have to be a muscle-bound Austrian to get the job done.

7. Major Alan Schaefer (Predator)

Major Alan Schaefer is keeping himself busy trying to rescue stranded airmen in Central America. He doesn’t count on running into the Predator, a vicious, tentacle alien that had made a name for itself by picking off the locals. Schaefer battles the Predator through the jungles and in mud pits, eventually tossing aside his weapons to take on the beast mano-a-alien.

6. Sarah Connor (Terminator 2: Judgment Day)

Sarah Connor had a tough enough time in the original Terminator; now she’s got to protect her son and the entire future from angry robots. Linda Hamilton appeared onscreen with bulging muscles and a shoot-first attitude, which served her well through the film. Sarah holds her own against both the T-1000 and Arnold Schwarzenegger – not an easy thing to do.

5. Alice (Resident Evil)

You’ll have to excuse Alice’s getup; while interesting, it’s not exactly the type of outfit that will give her any protection from the undead. Still, she manages to get the job done no matter what ridiculous attire she’s stuffed into, fighting all manner of zombies, monsters and evil-doers unleashed by the Umbrella Corporation. Milla Jovovich brings an icy, come-get-it personality to Alice, making her a surprisingly effective action heroine.

4. Richard Riddick (Pitch Black, Chronicles of Riddick)

He’s not the most pleasant character to spend time with – in fact, Riddick is downright hostile most of the time – but he’s almost perfected the role of badass action hero. Riddick swaggers through his films with a scowl and a sidearm, taking on enemies ranging from nocturnal alien bats to quasi-undead, planet-destroying marauders.

3. Snake Plissken (Escape from New York, Escape from LA)

The future must have looked pretty bleak in 1981; Escape from New York takes place in a 1997 where Manhattan has been turned into a maximum-security prison. Snake is about as foul-tempered as Richard Riddick, but is just as effective as an action hero. He sneaks into NYC, rescues the president, defeats a prisoner-turned-warlord and manages to issue pithy one-liners while he’s at it.

2. Luke Skywalker (Star Wars trilogy)

Why Luke and not Han or Leia? The lead characters in the Star Wars trilogy all seem to do the same amount of action hero-ing throughout the franchise. The deciding factor came down to the fact that Luke does more. He flies an X-Wing in a dogfight, engages in shootouts with Imperials…and fights with a lightsaber. Throw in destroying the Death Star and redeeming Darth Vader and you’ve got a well-rounded action hero, even if he is a bit of a goody two-shoes.

1. Ellen Ripley (Aliens series)

Ellen Ripley would mop the floor with most of the characters on this list, and then she’d have time to repair her starship later. Nothing can stop this woman; not inept shipmates, not bloodthirsty aliens and certainly not something as trivial as death. Sure, her presence on a starship is probably the kiss of death for the vessel and its crew – man-eating aliens seem to follow her around – but she’ll come out of things unscathed, even if her companions don’t.