The Half-Life 2 Cinematic Mod has been around forever, and in that time has proven fairly divisive. Sure, it adds some lovely effects to the game, but it also makes so many changes that some feel it loses a little of Valve's original vision for City 17 and its surrounding countryside. The "improved" character models are a particular bone of contention.
I could never get past the latter, with almost everyone in the mod looking like a Baywatch reject, but if all you care about are environmental effects and the crusade to make a game that's nearly ten years old look brand new, you might want to watch the new video below and see how far the mod has progressed since its inception back in 2005.
If you can meet its surprisingly hefty specs (at least for the full range of effects, considering the game's age), you can download the mod below.