L4D2 vs Portal 2

[n1zm0]

Extremely well done easter egg in a custom map for L4D2 Suicide Blitz 2 which you can get here from Valve themselves (http://www.l4d.com/blog/post.php?id=5693)

0mE94ocfx9k

[403Gemini]

That is pretty freaking sweet :)

[eglove]

pretty cool minus the OMGAWD girl commentary