As far as great ideas that were made into so-so films goes, the Highlander series has to be in the top five of all time. In my opinion it would be number one in that category, but that's just me. The popularity of Highlander has survived so long as a landmark in pop culture because its idea is incredible. It stays with you. The mythos of the immortal warrior battling on till the end of time and the quickening is unforgettable. It is also one of the coolest archetypes that fiction has ever produced. Until he loses his head the Highlander is doomed to live forever. Even if he is "killed" he will return to fight again. Everyone he meets will seem like a temporary shadow to him to be swallowed by time. He's popular for the same reason that everyone likes Wolverine. Same awesome character concept. Yet all of the Highlander films, even the cult classic first are only just alright. Possibly why talks of a remake are in progress at this very moment.