Wargame Airland Battle may quite possibly be the best RTS game I have ever played and I have played a lot of them. Airland Battle certainly goes to the top-3 anyway.
In 1970s and 80s Cold War gets hot and it's your job to command NATO or Warsaw Pact troops. There is an alright single player campaign with interesting innovations and relatively challenging AI. That however is mostly training for multiplayer, because that's where the most fun is going to be.
We Wargame players always like to remind people about the fact that Wargame is not Command & Conquer. In most cases you can't just send tons of tanks against enemy and expect the side with more units to win. Enemy is propably going to be hiding in cover in an innocent looking forest with ATGMs that may take out one third of your units and suppress the rest before you even spot the enemy.
No, you have to take into account all sort of things. I'm not sure how to explain clearly enough how many things, so I figured a bunch of examples could do the job.
You need to have command vehicles that can claim sectors and give you more points. You should also have at least something in reserve guarding these CVs (or artillery units for example) because many players like to send special forces in choppers to take out these expensive and vulnerable units. You have to keep your units supplied because your costly heavy tanks are going to be useless without fuel or ammunition. You need to have AA because there are propably a bunch of tank killer planes or choppers waiting for them. You need recon vehicles because most units (especially armored ones) have poor optics and they can't really shoot if you haven't spotted their targets for them.
The list just goes on and that's what makes Wargame cool.
In other words, Wargame series is more complex and way more realistic than standard RTS games. There are over 800 Cold War-era units from 12 nations. They all have their own stats like eg. armor (frontal/side/rear/top), weapons (type/range/precision/power/guidance system etc.), speed (in terrain and on road), size or experience. Sometimes the fight is won by the player who knows the technical data of the units better.
Of course you aren't going to use all these units at once when you play. Wargame Airland Battle has an innovative system called "decks" that define what limited amount of units you have available. Basically you can either make a standard deck in which you choose from all the NATO or Warsaw Pact units the ones you want. Often it is more interesting to choose some limitations for your deck and get some bonuses in return. You can choose to use one specific nationality, to specialize as an armored deck or marine deck for example, or to have only older units. Players can have tons of different decks that can specialize in specific roles and strategies.
Oh yes, the strategies. I love the way you can get enemy totally off balance with a successfully pulled cunning plans. Once we managed to attack an enemy reinforcement sector with choppers full of special forces and a command chopper. It was hilarious when we took the reinforcement point allowing me and my team mates to call in heavy armor right behind enemy lines. The poor enemy team got stuck between two fronts.
Still, you shouldn't be intimidated by the amount of stuff to learn even if these things weren't somewhat familiar from other games. Play some singleplayer campaigns against the kind of challenging AI. Go watch a couple of Wargame videos on Youtube because there are some guys who really know what they are doing. Lastly, you can play the campaigns of the previous game, Wargame European Escalation, because they actually teach a lot of basics in a humane pace. It's not the end of the world even if you happened to loose a multiplayer match.
TL;DR: What im trying to say is that Wargame doesn't really get old like many other games because every match is at least a bit different. Wargame is fun because there are so many strategies to use and anything can happen on the field. That's why it's also challenging always allowing players to get better at it. Wargame combines depth and realism with inventive strategies and kind of Starcraft-like need to react fast to changing situations. If that sounds good, I sincerely reccommend Wargame Airland Battle (as we wait for the sequel).