What do you hate using but are forced to use?
bayareaguy: Some of my clients use Windows Server 2008 on remote colocated blade servers.  It sucks because it's difficult to manage, it constantly raises useless authorization dialogs and it's terribly inefficient at even the simplest operations like copying files.  To make things worse many operations have to be done using DRAC controllers and a broken IE interface over a slow network.  Linux is a viable alternative and some are moving to it slowly but in many cases historic developers and programs are tied to Windows.