muy pocos juegos soportan multimonitor, en algunos que no lo soportan por ejemplo fallout 3 (juegazo) puedes de todas formas hacerla en modo SPAN, con drivers viejos y windows xp, en win vista, por el momento, no.
para trabajar está buenísimo 2 monitores, antes de pasarme a uso exclusivo de laptop siempre usé 2 monitores.
te dejo lista de jugos que soportan multi monitor:
RailWorks (PC) supports double and triple monitor displays when not full screen. When RailWorks is set to full screen, Desktop Spannning must be used. This is an issue, as only WinXP supports Desktop Spanning.
Microsoft Flight Simulator X[citation needed]
Microsoft Flight Simulator 2000[citation needed]
IL-2_Sturmovik (WW2 flight simulator)
Supreme Commander and World in Conflict (DX10 in multiplayer) both support multi-monitors in a dynamic manner of effectively displaying two aspects of the game simultaneously.[15]
Uplink (PC) features a multi-monitor option that utilizes the screens of two networked computers.[citation needed]
Early versions of DOOM (1.0 and 1.1) permitted a three-monitor display mode, using three networked machines to show left, right, and center views.[16]
X²: The Threat (PC) often cited as one of the first video games to utilize a multiple monitor setup[17]
Burnout Paradise (PC), a racing game[18]
DiRT 2 (Eyefinity only)[citation needed]
R.U.S.E., an upcoming WWII Themed online Multiplayer RTS game.[citation needed]
Clear the Swarm, a web game which utilizes dual screens, a primary for the main game and a secondary for additional information[19]
Test Drive Unlimited works in SPAN mode using older NVidia drivers under Windows XP.
Fallout 3 works in SPAN mode using older NVidia drivers under Windows XP. It does not work under Extended Desktop in Windows 7, since extended desktop cannot define one large i.e. 2048x768 or similar spanned resolution.
Ship Simulator 2008