I know nothing about displays, but am looking for one.

[WarpedByTheNHK]

I wanted to get a new TV or computer monitor that would be primarily for playing Shmups for the Xbox 360. I have heard that most LCD TVs have a decent amount of input lag, so I wanted to be careful about what I bought. I also would like the TV to be rotatable. I don't care about picture quality as much as lag, so long as I can see everything going on in the games. Lastly I would prefer it if the TV was readily available somewhere, so I don't have to just hope I run into it someday.

[HydrogLox]

When I looked into it the 23 inch Dell UltraSharp U2312HM seemed to be the "go to" rotatable/low-input lag display. You can hook up HDMI via a DVI-to-HDMI adapter or you can use an Xbox 360 VGA cable. The monitor does not support audio so you will need to send that "somewhere else" and when using HDMI/DVI you will need an Xbox HDMI audio adapter (Xbox HDMI AV cable) for analog audio on any XBox 360 or digital audio (S/PDIF - optical audio) on pre-S models - you won't need the audio adapter if you use digital audio on an Xbox 360 S (EB Games/GameStop may have used audio adapters from RRODed Elites). The monitor only rotates one way - which isn't usually a problem with tate-able Xbox 360 games as they tend to go both ways. However some retro-console games (attached via something like a Micomsoft XRGB-mini scaler) want to rotate the "other way" - just undo the screws on the mounting hub and rotate the hub 180 degrees - you may have to drill out one of the alignment holes for a perfect fit.