The Winner of the The Buddy System competition is none other than hermanJnr. with a fantastic little map pack complete with custom voice acting, new character animations and a pretty decent play time.
In Black Mesa: Dual Hazard you discover your would-be buddy, a British security guard named Watson, amongst the disarray of the resonance cascade. After fetching him some medical supplies and dodging several nasties along the way, the two of you embark on an adventure to reach the surface. Along the way the two of you are required to aid one another multiple times to the point where you really start to look out for the guy.
Personally, I found the details throughout the map a little lacking, and relying on Watson's puny 9mm pistol was quite a slow burn at times. I would have gone further and made some changes to the weapon damage and model itself, giving Watson a 357 and a more unique appearance. However, the numbers speak for themselves and this entry came out on top.