Society seems designed to take advantage of stupidity, and it pisses me off. Invasive advertising is just one example. Feel free to pit things that seem to exist solely because there are people stupid enough to make them viable.
Well, an obvious one is the (UK) lottery. (I imagine most national lotteries are similar).
What pisses me off is that the BBC promote it.
What pisses me off even more is that when the jackpot gets large I contemplate entering it.
“Extended warranty? How can I lose?!?!”
–Homer Simpson
Cigarettes.
Walmart - all the excesses of capitalism and globalization rolled into one, and people support it.
Cancer insurance. It just is not worth the money and is promoted using the publics fear of cancer. 
[sup]Is that stupidity?[/sup]
Spam and telemarketing.
Foil. That is right, foil. Regardless of how shiny it is, those foil swans scare the hell out of me.
Most (if not all) shows on MTV.
Las Vegas. It can be fun losong all your money. Right?
Email spam. I mean, how fucking stupid do you have to be to respond to one of those things?
And speaking of which, the stalwart, um, “entrepreneurs” of Nigeria.
Hold on there junior, extended warranties are good sometimes…
Religion
Astrology
Reflexology
Numerology
Reality TV.
Diet pills
Casinos advertising that they have the slot machines that have the highest percentage pay outs - 97% for example. 
All Bush campaign ads.
Corporate radio.
Sheep…I mean, people hear the 10 same shitty songs enough times, and they are off to the record stor—no, off to Wal-Mart to buy the cd. Then they are pissed off when there is only one “good” song on it. “I am not brainwashed, I thought the entire cd would be good.” Um okay that’s why that “artist” will have another cd out next fucking week because so much attention is paid to the “craft”.
Shit, I am starting to rant/hijack. This really pisses me off. The angry smiley is not nearly angry enough.
Yes, County, all Bush campaign ads. Perfect example.
Stupid lawsuits. So ya got injured after you got way too drunk and pissed on a light socket? Too damn bad - YOU are at fault. Don’t try to hold General Electric and Coors Brewing collusively responsible for your stupidity.
Credit cards. Tell me why these can’t be replaced with debit cards tied to your checking account? You run out of money, card gets rejected, no debt incurred.
2WD SUVs. The SUV was designed for a reason - and that reason is NOT “taking little Tyler to kindergarten” or “picking up Dakota and Destiny from their wind lesson”. If you don’t go offroad, you do NOT need an SUV. It’s the fucking yuppie scum responsible for the 2WD SUV. Come to think of it, those things ain’t SUVs. They’re minivans.
The Atkins diet craze. I swear, if I hear one more damn thing about carbs…
The QWERTY keyboard. Why are you still stuck with a 120 year old hack that has since outlived its usefulness? Try a Dvorak instead.