There have been several times I have asked in interviews (job & media) to name the worst video game I have ever played. My answer has always been something along the lines of:
I won't say E.T. on the Atari 2600 because that would be too easy. Instead I'll say Prince of Persia on the Philips CD-i. I played Prince of Persia when it first came out on the Apple II. I remember being surprised that a game of this quality was launching first on the Apple II because at the time the Apple II market was almost completely dead. It had such great game play and those beautiful rotoscoped animations. Then it started to get ported to other platforms and it seemed that with every port it got a little worse. It was a CES show in Vegas where I played it on the Philips CD-i and was just amazed at what an unplayable piece of crap it was. Not only did it play like crap, the animations had been cut down so much that they looked like crap too. And Philips was trying to sell this system as the latest and greatest new system and it couldn't even play a game that had launched on the Apple II.
Now granted there were some versions of the original Price of Persia that added some cool touches, the Super Nintendo version was pretty cool if I remember correctly, they added better boss fights and some other things. I remember feeling completely ripped off with the PC VGA version as it was just a thin coat of paint over top the DOS EGA version.
But now it looks like the classic version is getting a complete face life for XBOX Live Arcade and it looks pretty sweet.
Just hope you didn't mod your XBox 360 if you want to play it. See: Modded Consoles Blocked from XBox Live. If I had an XBox I would have modded it to get around region locking on games. I've said it a 100 times, I am not willing to buy a next generation game system here in Australia and then be screwed if/when I return to the U.S. I brought my XBox, PS2 and Gamecube with me from the U.S. and if I want to buy new games for them I have to have somebody in the U.S. buy them for me and ship them over because of region locking.