iZombie is one of the more recent television series to feature a complete explanation of the backstory in the intro. The comics the series was based on were illustrated by Michael Allred, and he provided the illustrations that greet the viewer when the first episode starts.
The intro kicks off with a woman at a checkout aisle picking up a copy of George A Romero's immortal classic, Night of the Living Dead, which is followed by her narration, "How often can you say you've been changed... really changed by a party?"
From there, it goes into a montage of comic book panels explaining what happened to her. It begins with "The Beginning," which shows a zombie outbreak on a boat, and the woman looks to her forearm and sees that she's been scratched. The caption changes to "The Infection."
Cut to a beach with the burning boat in the background, and a new caption, "The Transformation" appears as she emerges from a body bag, now an undead zombie. Then it's "The Ex-Fiance" and "The New Job" shows her working as a coroner with whitened hair.
While it isn't yet clear why, she's eating brains with hot sauce, and "The Ally" pops up, indicating her co-worker is on her side. She then has "The Visions," followed by "The Partner" and "...But I'm a Zombie," closing it all out. It's a brilliant intro, and with few words, it conveys the entire backstory of the show in under 30 seconds.