I've used my old heroquest stuff many a time for d&d sessions, and we always play heroquest with roleplay, in character. The straight up dungeon crawl of it makes a nice casual, improvised session.
Heroquest, by its design is excellent for a GM + single player, as well.
They're a classic for a reason, and that reason is consistency. You buy one today, you can count on it being a good knife, just like the one your dad bought. And, most likely, your kid will be able to do the same.