I'd say the Arma and Company of Heroes series.
In Arma, there are alot of stuff that could be used, but could end horribly for you and your team if not enough thought is given. Seriously they are too many list.
Company of Heroes is a strategy game that doesn't use the old "buy the heaviest tanks and rush the enemy" system. Yeah, tanks are very powerful and expensive, but they are nothing that a cheap Anti-Tank gun can't take down. In the mean time, an AT gun crew is a good clear target for one of your snipers to practice their art. Infantry cannot be used mindlessly since a single machinegunner can tear down an entire platoon in seconds. There's also a cover system. A covered soldier will last a lot longer than one in the open, for that reason theres the possibility to place sandbags around your base or your outposts. And the territory system can be annoying. If a supply line is broken, your army won't receive any ressources from the territories that are not connected to your base.