This is the mods I normally use when playing, it makes the game somewhat realistic and quite fun, I also use the multiplayer mod (included here) because I play with my friend sometimes...

This makes Black Mesa somewhat realistic, and also gives some tweaks, such in signs, textures, and some lore-friendly design choices.

This is a collection that is more realistic than the previous, however it cannot work on peer to peer, only on singleplayer or dedicated.

This makes your Left 4 Dead 2 somewhat realistic while also being server-side, meaning you can play it in the normal peer to peer multiplayer with this.

This makes Half-Life 2 somewhat realistic and also a bit lore accurate I would guess?...

A collection that has a bunch of realistic mods for Ravenfield on the Workshop, with all of this, your Ravenfield will be somewhat realistic, atleast in the gameplay sense.