The Asus HD4670 is an excellent video card - it's cheap, uses little power, and can run most (if not all) new games at mid-high settings on lower resolutions.
I bought it as an upgrade from my old Nvdia 7600, and I have not been disappointed: its incredibly low power consumption (requires no extra power lead) was a massive drawing point to me, as I have a tired, old PSU so any other graphics card would require that to be updated too.
However, with only 512mb of DDR3, it does have issues with higher resolutions and shouldn't be considered on a serious gaming rig, espically with its very medicore clock speed of 750 mhz. That said, for home theater use, it's very difficult to beat it for its price. In fact, it almost seems this card was made for home theater PCs - it has a low power consumption, a fairly quiet fan, and full HD output (including sound via HDMI cable). It would also be a great card for someone wanting to do some low-end gaming on a budget, or who uses 2D image editing software (ie Adobe Photoshop) often.