The type of articles that are most likely to fulfill Wikipedia's promise have three characteristics:
1. The truth is absolute, not subtle.
2. Everybody knows a little something about it, but few people know everything about it.
3. The subject is interesting enough to attract a steady stream of potential proofreaders.
For example, the question of which countries drive on which side of the road is binary -- either left or right -- and it's fixed by law, so you can't argue about it. With almost 200 countries in the world, no single contributor will have direct experience of every country's highways, but with the whole Internet tossing in, you're sure to find someone, somewhere, who knows the answer for each country. If you check the History and Discussion, you'll see that some myths have tried to sneak in, but there are enough editors to catch these.
Wikipedia's List of films that have been considered the worst ever also fits this profile. They have a strict definition of "worst ever" (either cited by reputable sources as the worst movie of the year, or been on a list of worst movies.), and the article has enough traffic to keep the list complete, current and clean.