I have two Dell monitors, 20", one is 1680x1050 and the other is 1600x1200. They are both hooked up to an old desktop computer that I have used one time since I got my MacBook Pro. My "primary" secondary monitor is my TV which runs at 1920x1080. Which one makes more sense to keep as a backup secondary monitor for my laptop which runs at (1440x900)? I don't use the computers here for any design/audio/video work. My plan is to take the desktop computer apart and put the one remaining monitor into storage.