According to this InfoWorld article:
1. Invasive advertising.
2. Re-inventing the wheel.
3. ‘Leap of faith’ links.
4. Attention-deficit Web sites.
5. War and Peace length.
But my favorite pick from this article is right-column blindness:
“We are now seeing right-column blindness, where users do not see information and links down the right hand side of the screen. This occurs because the right hand column has become known for advertising,” Cunnington said.
While advertising is medically known to cure erection problems, its side effects include vision impairment. Don’t say I didn’t warn you.