Im buying some Bose speakers for my PC in the next few months and thought it would be beneficial to upgrade my DVD drive to a Blu-Ray/DVD combo to watch in HD aswell as get great sound. I was talking to a friend and he said that there isn't any software (or very little) that actually plays full HD films.
I don't know what the current line-up is but I'm running PowerDVD 8 Ultra. This will play blu-rays ay 1920x1080, which is 1080p (I think it is anyway). I would make sure you have a display capable of displaying it or it isn't worth getting it.