if you have a $200 budget, I would recommend getting the ASUS VH242H. I'm have two of them now, waiting for more money to get that third one.
They are great, 23.6'' and 16:9 aspect ratio.
Also! Once you remove the case/bezel. It significantly decreases the space between monitors. Check out my thread where I took the monitor apart to find out exactly how much bezel you can lose. http://www.tomshardware.com/forum/272533-33-multi-monitor-setup-bezels