If you design sites, create content that goes on the web (whether that be words or pictures or whatever), or develop and code sites you need to read this: "The 65 Most Annoying things about the Web Today" from UXByDesign.org blog.
This article lists a number of specific annoyances and issues for just about anyone that surfs the internet and uses website, from a variety of different categories including design, information find-ability, content strategy, forms, technology and functionality.
Some of my top favorites are:
- Splash screens
- Illegible text
- Busy backgrounds
- Contact info (namely the lack of a phone number)
- Unscannable article content
- Spelling and grammar
- Small product images
- Unreadable captchas on forms (I really hate this one)
- Pop-up ads
- Interstitial web-pages
- Internet Explorer 6 (yes, please make it crawl away and die)
- Entire sites built in Flash