Underrated TV Show from the 90's. Proof of its influence is the fact that the titular characters' laugh is so deeply ingrained into our psyches. Uhhhhhhuhuhuh.

MTV cartoon airing from 1993 until 1997. It was found to be hugely popular, particularly among men in their twenties and teenagers, and resulted in a full length theatrical movie, holiday specials, and a spin-off series featuring the character Daria. Because it did technically air on MTV (back when MTV was interested in music), during breaks in the storyline music videos would air with both characters "reviewing" and commenting on it, somewhat akin to what Mystery Science Theater did with cheesy sci-fi films.
The actual storylines followed two 15 year old numbskull boys as they went through everyday life and often wound up in bizarre and hilarious situations. Their basic motivation was always to "score" which of course they never did. Along the way and, on the side, their adventures would often result in one or both of them getting arrested, getting beaten up, getting maimed, or occassionally just releasing general havok themselves. Their trademark was the classic and strange laughter which never seemed to end.

Physically Butt-Head had dark brown hair, braces, and a large nose while Beavis had blonde hair, a bit of an underbite, and a somewhat pointed nose. Behaviorally Butt-Head was typically the more "focused" (which isn't saying a lot) while Beavis was typically more manic. These could be occassionally reversed however with Beavis becoming more contemplative before Butt-Head tried to "kick his ass" and snap him out of it. They frequently got into fights but continue...

Beavis and Butt-Head are two 15 year old kids that act like they don't have too many brain cells from all of the meth they use. Basically a show that I could have lived w/o watching in my childhood considering that I was 8 years old when the first episode aired.
It is a show that makes you more stupid just because you are actually wasting your time watching it. The only thing that it inspired me was how to be really good at fucking shit up and consuming time that I could have used to do something more useful or productive.
I feel that it would have been better if Beavis and Butt-Head weren't on basic cable to rot little childrens minds but rather published elsewhere. I must say, it had to be one of the most hilarious shows ever broadcasted in us history.