I don't know if VLC supports GPU acceleration (I didn't know video players did!)
But it will play just about anything
My god! VLC plays everything but suxx with AVCHD and h.264.
And does NOT use GPU!
I use Mirillis Splash for h.264 and it uses gpu accelreation (only vista and win7 are supported so far i guess).
This is free software.
PowerDVD also uses gpu but it costs quite much and gives lower video quality than Splash