Another bit of annoying code I forgot to add to the poll would be framesets code.

Three things I dislike are:
As many browser windows as I usually hold open on my desktop, my system hits a "resources unavailable" limit with fewer sites open in my browser if I happen to be researching information and hit a predominance of framed sites.

Another issue, albeit more philosophical, is that framesets stretch or even break the paradigm of the worldwide web--presenting, displaying, transferring, and indexing page information and not parts of a set of components appearing as a page. Also, since HTML was designed as a SGML markup language subset, incorporating framesets into HTML further weakens the relationship of HTML and SGML (and now, the XML model)....

The last thing I hate is that framesets make it so easy for someone to take my site pages and make it look like my resources are theirs!

It happened to me a few months ago: while checking my search engine rankings,the page right above and below one of my pages were framesets sites using my page as content frame source (and incorporating my hard-earned otimizations into their site with little effort on their part). Both happened to be college undergrads wanting a shortcut to my page's table of information; emails to one got my content removed and replaced with a nice text link to my page, but the other one took a second email to the university webmaster who got the site removed from the university domain space.)