I love sectioning off zones in multiplayer games via turrets. 
Controlling a whole room/area by sectioning off entrances with turrets mixed with a good old shotgun to hinder people from rollin' up and fucking up my turret gives a really nice, solid feeling.
Does anyone know of any good multiplayer games with deployable turrets in them? 
Here's what I've got so far: 

• Killzone 2-3 
• Team Fortress 2 
• Modern Warfare 2-3 & Black Ops 2 

Halo 4 has some pretty good turret action. They're not overpowered but annoying enough that you can't ignore them and they take a while to deploy so you have to pick when you drop one.

Hawken has them, but they do very minimal damage, to the point that they would need ~15 seconds of line of sight AND for you to be stationary to do enough damage to kill you. So all they really do is cause you to shoot at them for a second, and the gunfire gives away your position on the radar map, and then several enemies start heading you way.

@TaliciaDragonsong said:

Laptop Gun, Perfect Dark.

Aw man, good memories attached to those words. I'd totally forgotten about that game until just now.