Subscribe to download
Animated Borderlands styled loading screens - L4D2 Campaigns

You can find the workshop download for the L4D1 campaigns here.
---------------------------------
DISCLAIMER: It's not perfect. It animates after the game has loaded 50% of the map. Between 50-80% it will be choppy, then the last 20% it will animate smoothly. The percentages are based on the progress bar at the bottom.
---------------------------------
This mod will change all the Left 4 Dead 2 campaign loading screens into an animated version, similar to the loading screens seen in Borderlands.

I wouldn't recommend using this on weaker PCs, it might be too choppy for you.