“I hate stupid people. Not only are they annoying, they're also boring.”
Related quotes

“I like long walks, especially when they're taken by people who annoy me.”
The Abolition of Work (1985)
Context: The demeaning system of domination I've described rules over half the waking hours of a majority of women and the vast majority of men for decades, for most of their lifespans. For certain purposes it's not too misleading to call our system democracy or capitalism or — better still — industrialism, but its real names are factory fascism and office oligarchy. Anybody who says these people are "free" is lying or stupid. You are what you do. If you do boring, stupid monotonous work, chances are you'll end up boring, stupid and monotonous. Work is a much better explanation for the creeping cretinization all around us than even such significant moronizing mechanisms as television and education. People who are regimented all their lives, handed off to work from school and bracketed by the family in the beginning and the nursing home at the end, are habituated to heirarchy and psychologically enslaved. Their aptitude for autonomy is so atrophied that their fear of freedom is among their few rationally grounded phobias. Their obedience training at work carries over into the families they start, thus reproducing the system in more ways than one, and into politics, culture and everything else. Once you drain the vitality from people at work, they'll likely submit to heirarchy and expertise in everything. They're used to it.

“I have a theory that the Internet makes people stupider — and also FOX News makes people stupider.”
Larry King Live interview (2010)
Context: I have a theory that the Internet makes people stupider — and also FOX News makes people stupider. You know the Pew group did a study recently and they found out that 10 years ago, Democrats, Republicans and independents basically got their news from the same sources, probably more from CNN, for example. Then we had this polarity. … We do have two Americas. We have the America that's living in reality. The people who understand that Obama is a centrist liberal from Hawaii who is trying to dig us out of the hole we're in. And then we have this other FOX/Matt Drudge/Rush Limbaugh reality where he is a Muslim sleeper cell, Manchurian candidate who was sent over by his Kenyan father …

“Do you hate people?”
“I don't hate them… I just feel better when they're not around.”
Source: Barfly

“Elaine: Ugh, I hate people.
Jerry: Yeah, they're the worst.”

“It's only because of their stupidity that they're able to be so sure of themselves.”
Variant: It is only because of their stupidity that they are able to be so sure of themselves.
Source: The Trial

As quoted in the article 'End of an Era?' in Live and Kicking magazine (2000)