Homer Simpson, voiced by Dan Castellaneta, is the patriarch of The Simpsons and is definitely the main character.  Homer is an overweight, slob and a terrible father, but genuinely tries hard.

Homer previously had a job as safety inspector at Mr. Burns' Nuclear Power Plant, but good luck finding out what he's been doing for a living the last few years.

Homer Simpson Quotes

Homer: You're welcome to watch anything you want on TV.
Bart: TV Sucks.
Homer: I know you're upset right now so I'll pretend you didn't say that!

Homer: (Wearing glasses) The sum of the square roots of any two sides of an isosceles triangle is equal to the square root of the remaining side!
Man: (From inside a bathroom stall.) That's a right triangle, you idiot!
Homer: D'oh!

The Simpsons Quotes

Lisa's Brain: Poor predictable Bart. Always takes 'rock'.
Bart's Brain: Good ol' 'rock'. Nuthin' beats that!
Bart: Rock!
Lisa: Paper.
Bart: D'oh!

Homer: You're welcome to watch anything you want on TV.
Bart: TV Sucks.
Homer: I know you're upset right now so I'll pretend you didn't say that!