Movie adaptations of video games tend to be pretty poor. They've almost never been helmed by the folks who actually created the games, though. In an interview at PC Gamer, Valve's Gabe Newell reveals that the company could bring the original Half-Life to the big screen itself:
Where we got into this direction was after Half-Life 1 had shipped. There was a whole bunch of meetings with people from Hollywood. Directors down there wanted to make a Half-Life movie and stuff, so they’d bring in a writer or some talent agency would bring in writers, and they would pitch us on their story. And their stories were just so bad. I mean, brutally, the worst. Not understanding what made the game a good game, or what made the property an interesting thing for people to be a fan of.
That’s when we started saying ‘Wow, the best thing we could ever do is to just not do this as a movie, or we’d have to make it ourselves.’ And I was like, ‘Make it ourselves? Well that’s impossible.’ But the Team Fortress 2 thing, the Meet The Team shorts, is us trying to explore that.
Although some are better than others, the Meet The Team shorts do show that Valve has a flair for this sort of thing. Whether it can captivate an audience's attention over a full-length feature remains to be seen, but I'm cautiously optimistic. I'd certainly rather watch Valve's attempt at retelling the Half-Life story over an outsider's adaptation of the game.
Then again, part of me hopes that Gordon Freeman never walks the red carpet. The original Half-Life holds a special place in my heart (up to the Xen levels, anyway), and I'd hate to see my fond memories sullied by a movie port that sells the original short. There's little doubt in my mind that Valve could tell a better Half-Life story than Hollywood, but given how universally disappointing video-game adaptations have been to date, that isn't saying much.