One thing which really gets up my nose is architectural websites whose rules of operation you have to learn by trial and error. So do their designers, who rattle on about the web being an interactive experience.
I always agree - and interact by leaving the sites.
There are some amazing sites where trial and error and mystery navigation are part of the experience. But these are not architectural sites and are created by talented and often strange people having and giving a lot of pleasure. www. djomba.com and www. yugop. com are two examples.
Another nostrildistorting trick affected by designers is sideways text.
I have friends who can read upside-down text and, in the old days, typesetters proof-read straight off the reversed metal type. But if the Intelligent Designer had intended us ever to read sideways text, She would have given us a swivel joint instead of a limited-exibility upper lumbar vertebrae.
Trying to read sideways text on screen involves major discomfort, squinting and a tendency to fall sideways off your office chair. So you don't bother reading it. Maybe there's a lesson there for designers. And their clients.