First two are really good, the fourth film getting third place for it's unique setting alone, and the fifth only not getting last place because there's literally no redeeming qualities about Wrong Turn 3. 3, 4, and 5 are all varying degrees of awful so they're basically interchangeable.
Four at least had some potential with the setting & the actual look of the brothers. Parts three & five managed to completely fuck up everything that could've been interesting. Even with Doug Bradley part five still turned out horrible, which saddens me considering he was literally the only actual actor in the movie.