CP3S said:
Half-Life: Escape from City-17.
http://www.youtube.com/watch?v=ZKffQO2UZBE&feature=relmfu
While far from flawless, these guys did a fantastic job on the little of it they did make. I'd love to see the whole thing, or a feature length film made by them. Unfortunately, this is from back in early 2009 with no sign of life since then. Beside the trailer I posted, there is a five minute long "part one" of the feature up on youtube, but the second part promised to be "coming soon" never showed up. I've always grimaced at the idea of a Half-Life movie, but man, these guys did an amazing job for a next to nothing budget.
have you seen Beyond Black Mesa? http://beyondblackmesa.com/