1080 upconverters

Hello all, I just purchased a 1080p Samsung LCD TV. I tried out a DVD on my old player yesterday and saw that the screen resolution wasn't nearly as good as I thought it would be. I looked into buying a 1080p Upconverting DVD player but held off to find out more information. All I don't understand is should I go ahead and just buy an HD DVD player? Are HD DVD's basically the same as upconverting regular DVD's? Obviously the upconverters are a lot less inexpensive so why should I or shouldn't I just stick with the upconverter instead of buying an HD DVD Player? Thanks!!!!!