I've owned the first North American release since back in the day. I foolishly did not buy the add-ons, even when I found one cheap back then. I only had my sister and a cousin to play with, so eventually my copy got shelved, but lovingly kept.
To my surprise, while searching for miniatures and such on Amazon, Hero Quest popped up! And not the old edition, but a NEW one! I was excited, especially after learning there was an Android application that FINALLY made the game playable solo! And then I found a Windows based program at Ye Olde Inn. So that's TWO now!
At first, I didn't buy the main game, just the expansions, but then decided to get everything I reasonably could.
If you liked the old one, try the new one! It's mostly the same game, albeit with re-imagined pieces and such, but very well done!