SWAT4, released by Sierra in 2005, is a great tactical first-person shooter that puts the focus on saving lives as opposed to taking them.
Unfortunately, the game doesn’t like dual monitor setups and most of the time bluntly refuses to load without the screen flickering like hell as it tries to work out what resolution to run at. Using Alt-Tab to flick between tasks sometimes cures it, but more often than not you have to go into Task Manager and end the process, which gives you an error message about not being able to set the resolution, recommending that you delete the Swat4.ini file.