npc_create_equipment (weapon_name); wait; npc_create (npc_name)

For Example:
npc_create_equipment weapon_ar2; wait; npc_create npc_citizen

First : ai_disable

Disable AI first , so they won't attack you.

2: Spawn npc like npc_create npc_zombie

*if you want all of zombies to be your friend....just skip the 3rd.

3: aim at that npc and ~ type in ent_setname (name)
Ex: ent_setname zombie

4:ent_fire zombie setrelationship "player D_LI 99"

*For lots of zombies or NPCs :
ent_fire npc_zombie setrelationship "player D_LI 99"

Relationship code:
D_LI = Like
D_HT = Hate

After this you can do something funny like make them kill each other.

Ex: ent_fire npc_zombie setrelationship "npc_zombie D_HT 99"

PS: You can use this command to all of the NPCs in HL2. but some of them wont follow you as Antlions.

HAVE FUN!!!

Then I spawned a bunch of zombies and watched the turret gun them all down hehe.
Its quite fun using this in parts of highway 17 near one of the thumpers. set 3 turrets up to do all the work while the thumper machine is on, or "ai_disable" and set one of the houses up near a antilon spawn as a fort. Place turrets on top of crates so they can fire through windows and then spawn 100 zombies or fast zombies and type ai_disable again while safley in the house.

I still dont know how to make them attack combine yet though.. also, I found out that you can't save it all after, coz when you load it again everything is back to normal, the turret attacks you etc. I was wondering if I could make some kind of script that I could run that spawns some turrets and makes them friendly.
Any clue's madmoron?