I switched over to using HDTV's as my computer display monitors years back, and have never looked back. The HDTV's work plenty fine for me, and I get WAY for bang for the buck.
I currently have 2 HDTV's (used to use 3, but dropped back to 2 and that's been fine). The first happens to be a 40" Westinghouse that I picked up brand new for $249, and the other is a 32" RCA that I picked up brand new for $130.
I am running using the built-in graphics of the AMD A10 CPU I happen to be using, and use the HDMI port from the motherboard to run video and audio to the 40", and then I have an adapter cable that connects to the DVI port from the motherboard and is converted to an HDMI connector to run to the 32".
I have NO dedicated video card, as the CPU's video provides plenty of horsepower to run both displays.
I am SUPER happy with the money I have saved using the above setup, and have no performance issues, with an added benefit of setting the Windows Default Audio Device to be the HDMI audio port for the 40" HDTV, which gives me adequate sound for things like playing YouTube videos or Windows Media Player tunes at the same time Sonar is running - as Sonar is set to use my audio interface and its ASIO drivers.
Bob Bone