Vice City is my favourite Grand Theft Auto game. Yet Grand Theft Auto IV has the best visual effects and physics in the series. What to do? I know. Let these guys rebuild Vice City using GTAIV's engine!
Using the OpenIV set of mod tools, two teams are currently working on recreating Vict City using Grand Theft Auto IV's engine. One team, Vice City RAGE, have released the above video, which is obviously a work-in-progress (since there's still janky textures and a distinct lack of pedestrians).
The other team, Vice IV, are doing exactly the same thing, and have this video to show for it.
Both look like they're doing a good job, but are forgetting the two best things about the original Vice City: a crisp blue sky and Mister Mister. Get both those working and they'll be set.