There are many things to pay attention to in choosing a computer gaming monitor. A typical case as of 2009 is a 20-24" TFT-LCD using a TN panel. Multi-monitor gaming requires a fast pixel response time (no ghosting), low electronics input lag (latency), good viewing angles, well-designed LCD stands, and preferably ultra-thin bezels.
Lesser-used Displays Edit
Plasma Televisions Edit
Organic Light-Emitting Diodes Edit
Some flavor of OLED display will likely completely replace LCDs in the eventual future - they are 10x as bright per watt, can come in very high or very low pixel densities, can be built very thin and 'edgeless', have nanosecond response, very good pixel depth, and likely none of the angular or polarization problems of today's screens. They are about 50 times as expensive as LCDs at the moment, so they are not seriously considered - mainstream consumer goods larger than a smartphone or MP3 player do not yet exist for the most part.
Cathode Ray Tubes Edit
CRTs, which plateaued at the popular 21" Trinitron tube and have gradually been displaced by LCDs, are sometimes used by gamers, particularly in the form of 'near-perfect' sets like the 24" GWM-FW900. It is rare to find CRTs used in multi-monitor setups because of the weight and footprint, the power expense, and the fact that not many were made with even modern DVI inputs, much less HDMI or DisplayPort, which dominate current gamer video cards.
Theoretically, a good projector gaming setup that's high-enough res is one of the Holy Grails long sought by gamers. Practical results are scarce, as the barrier to entry is so high. A single best-of-mainstream-class 1080p projector will still run you $2000, despite about a 30% pricedrop every year or so.
LCD panel types Edit
Thin-Bezel Models Edit
DisplayPort Models Edit
List of non-TN panels which have DisplayPort Inputs Edit
22" HP LP2275w
23" NEC EA321WMI
24" Dell U2410
24" HP LP2475w