Personally I believe that the PC version is better because the game mechanics are smoother than on Xbox, you can add more configs, mods, etc., change appearences and models, find more games, and get highter FPS. (These are just to name a few. The highest FPS you can get on xbox is like 30 something. The Xbox community is still big and strong there and I respect that but PC holds its place in my pick. This is just a random opinion to throw out there lol

Also another thing: If Valve shuts the servers down (which they most likely wont considering the game is still popular almost a decade later), the Xbox community wont really be able to play L4D ever again but Im sure people on the PC can find a way. (Ik this post is really irrelavant and late but yeah...)