Some examples of highly popular questions that 

- are there for "historical reasons"
- don't really fit anymore
- are outdated

I'll let others debate. Here we go:

- [Good website for wallpapers](http://superuser.com/questions/10775/good-website-for-wallpapers)
- [Windows 7 tips and tricks](http://superuser.com/questions/7622/windows-7-tips-and-tricks)
- [Which Windows tweaks do you use and they actually work?](http://superuser.com/questions/3864/which-windows-tweaks-do-you-use-and-they-actually-work)
- [How to sync bookmarks between Firefox, Chrome, and Safari on multiple computers?](http://superuser.com/questions/16530/how-to-sync-bookmarks-between-firefox-chrome-and-safari-on-multiple-computers) (totally outdated information)
- [What can I do with a home server?](http://superuser.com/questions/35310/what-can-i-do-with-a-home-server)
- [Underused Mac OS X GUI features](http://superuser.com/questions/15646/underused-mac-os-x-gui-features)
- [What's your favourite piece of (Linux) software nobody's heard about?](http://superuser.com/questions/2652/whats-your-favourite-piece-of-linux-software-nobodys-heard-about)
- [Do you run anti-virus software?](http://superuser.com/questions/561/do-you-run-anti-virus-software)
- [Hidden Features of Windows Vista](http://superuser.com/questions/12450/hidden-features-of-windows-vista)
- ["Must Have" Text/Terminal applications?](http://superuser.com/questions/18730/must-have-text-terminal-applications)
- [Why is Vista Disliked?](http://superuser.com/questions/4004/why-is-vista-disliked)
- [Most secure browser](http://superuser.com/questions/209708/most-secure-browser)
- [Best free codec pack](http://superuser.com/questions/5184/best-free-codec-pack)