I've played "The Dallas Quest" about 34 years ago, on my C64. I must have been around 13, yet it's one of the early IF games I remember more vividly — well, at least there a particular scene toward the end of the game that stuck with me, most of the plot has faded away in my memory now.
We all have seen thousands of ads, played hundreds of games, yet there is always some ad that keeps popping up in our minds from the distant past, and some games that we remember most, despite the hundred of better games we've played after it. Why? Who knows...
I wasn't a fan of the Dallas show at all, but I remember enjoying this game a lot. I can't really say why this, of all games, survived stronger in my memory than others — and I had played a lot of IF games even back then. If it's true that "time will tell" and that in all things the test of time is a proof by itself, then there must have been something special about this game that made it memorable to me.