Anti-hero: You must be delusional... And your cape's on backwards.
Hot teenage girl: Somebody save me! I'm so hot, young, and defenseless!
Antihero: Never fear! the antihero is here!
Using hella sweet kung-fu, the antihero subdues all of the hostage takers, frees the hostages, briefly makes out with a hot, young, teenage girl, and then frees the hero (after stealing his wallet).
Hero: Thanks to you the day is saved!
Antihero: Yes, yes it is. I rock. Pay me. Now.
But, as the antihero waits to get paid, he hears the sirens of police cars. Knowing that he is wanted in three states for identity theft, and impersonating George W. Bush, he hops onto his motorcycle, and drives off into the sunset, only to return another day.
The Antihero is someone with some of the qualities of a villain, up to and including brutality, cynicism, and ruthlessness, but with the soul or motivations of a more conventional Hero.
Anti Heroes- Beavis and Butthead in the episode where they save a man who has crashed in a light plane. They try to flag down a car so they can go and get a camcorder to film the wreck and sell it to television.
In the process they inadvertently alert the emergency services who save the man.
Subsequently they appear on "Rescue 911" where they are portrayed as bonafide heroes.