Below you can find a list of brands and model types of graphics cards that should be compatible with MPC-HC. This list is likely to be incomplete. Almost any graphics chip manufactured in the past few years supports DXVA.
ATI Radeon HD 2xxx series and newer
NVIDIA GeForce GTX 2xx series and newer
NVIDIA GeForce 7xxx series and newer
Details on which NVIDIA cards support H.264 and/or VC-1 bitstream decoding can be found HERE.