I prefer plot with options, meaning I want a story, and a preferred direction offered by the DM; some form of plot. But I don't want to hand-held, just pointed in the right direction. All adventures I design whether for personal games or publication, there is a definite goal in mind - deliver the package, rescue the princess, escape the pursuers. Just how to get there isn't set in stone, allow the PCs the freedom of deciding how best to pursue the goal.
I've played many total sandbox games, and honestly, they bore me to tears. I prefer an overarching story or plot that drives the goals of the PCs. Walking in the fog and fighting single encounters after single encounters without rhyme or reason is the kind of game I don't want to play.
And regarding HowandWhy's post of computer versions of these games... I'd rather be stabbed in the eye seventeen times then to ever play a computer game. I don't need some 3D modelers idea of what the terrain looks like - I see a better version in my head and it probably won't match what the 3D artist considers it does.
And this is coming from somebody who does 3D modeling from time to time, as I also incorporate some 3D objects for my mapping. I consider tabletop RPGs and computer RPGs as apples and oranges. And really, really, bad tasting oranges at that...