Not to rain on your parade, but... the whole Best Demo thing is a bit iffy at best, because most demos I know of don't end up in the demo section of the database (My own demo of the TSP included). I mean, basically all of the award winning titles had a demo released at one point, only not as demos in the AGS database, and thus not eligible for the award.
I don't know why people don't bother that much with the demo category, perhaps they think it's jinxed or something, or just unnecessary.
Not to take away any of the prestige in this category, it's still a great feat to win it.