The sequel does away with the deformable terrain and weapons on regular buildings, but now you can get wall-mounted turrets. Aside from turrets, even production buildings can be armed with weapons and you can freely swap all building-mounted weapons to your heart's desire, with some weapons allowing additional weapons to be mounted on top of them! And aside from regular walls and landmines, you can also play around with deformable terrain to limit where the enemy can enter into your base and funnel them into killzones. Only drawback to having all of these defenses is that they count into your population limit.ДЄdditionally, another game you may consider is Earth 2150. So as you can see, SupCom is a turtling enthusiast's wet dream. Has a limited range, limited ammunition and costs a lot to build and arm, but they blow incoming nukes right out of the sky. They're still visible if the enemy has LOS on them, but they can't shell them with artillery without actually seeing the target or force-firing at the ground (which the AI never does).ДЇinally, unlike the majority of RTS games with superweapons, SupCom has a defensive structure against them, too. Stealth field generators hide nearby stuff from radar. Sonar antennas similarly reveal all enemies in the water, including submarines which are normally hidden from both sight and radar. They also defeat cloaking and you can use radar built in range of the enemy's base to spot targets for artillery. Radar antennas not only show the location of enemies in real time at long range, even if they're under fog of war, but your turrets automatically open fire at incoming enemies even if they aren't yet in the turret's sight range. Tactical missile defenses are available, which automatically target and shoot down incoming cruise missiles at short range (with varying effectiveness). Only drawback is that you have to individually build the missiles and launch them manually, it won't fire on its own. Good for softening up tightly-packed attack waves or counter-battery fire against enemy mobile artillery.Д¬ruise missile launchers are available, operating at artillery ranges and hitting with enough concentrated damage to kill most units in a single direct hit. And yes, you can build multiple generators next to each other to create multiple overlapping shields to the point where the shield generators in the front recharge and reactivate before the ones in the rear fail.ДЇixed artillery guns are available, massively outranging almost all mobile units in the game.

Enemy units can still pass through the shield, and it also won't stop falling aircraft wrecks or nukes, but anything else is completely nullified as long as the shield has any charge left. Shield generators erect a bubble-shaped shield that drains a not insignificant amount of power while active (and unlike C&C TS' Firestorm Generator, SupCom shields are always active unless you manually turn them off), but will save your hide when your base comes under artillery fire. Oh, and they can also be built on water.ДЇor naval defense, torpedo launcher turrets are available and hit quite hard. Mobile artillery is the best way to kill them.ДЄnti-air turrets are not quite as high-powered, but mid-tier ones still inflict splash damage that can kill massed low-tier units quickly. Unlike most other RTS titles, anti-ground turrets are murderously powerful in this game to the point where they can massacre dozens of tanks of equivalent tech level while barely taking any damage. Walls are available and build very quickly and cheaply.

Supreme Commander's been stated already, but I'll recommend it anyway.

Supreme commander build templates