lucy24 - 8:15 pm on Nov 14, 2013 (gmt 0)
Sites that assume your monitor is 2000px wide-- and you're using all of it for the browser.
Does anyone in the world actively like sites that play music unasked? Someone must, or there wouldn't be so many sites that do it.
As a user of a less-common browser I'm also riled by sites that use unconditional UA detection to withhold content from me. I don't mind a preliminary message saying "Our site may not work on your browser but you're welcome to try."
I counted up recently and found that my front page (only) uses six fonts. But not for body text.