Look nowhere else if you're looking for a military simulator or not, because this game does both.
Community created gamemodes that feel completely different from the base game or further extending the features the game already has, making for unique gameplay whichever gamemode you visit.

The community in this game especially is great. I've played many online games for longer than a decade, ranging from RPG to arcade shooters, tactical FPS games etc. and the community Arma 3 has beats them all. It's more mature than what you'd find in many other games, everyone's ready to play tactical but are willing to mess around for fun. Some people are more serious and play arma as if it's a real life situation but it's easy to avoid those (or join them) by carefully picking the server you play on.You still find some bad apples here and there but they're the minority while in a game like overwatch it'd be the other way around.


Which DLCs to get?
The first question anyone interested in this game asks is, which DLCs do I need? To be fair, they're more expensive than the base game but that's for good reason.Devs need cashflow to keep the good updates coming and they're adding some good content.

Marksmen DLC is needed for more weapons & attachments, Apex adds a new map, some vehicles and a lot of of customization options (especially anti-thermal outfits that'll benefit you). Those two are a must but you can save up and buy them later during a sale.
Laws of war is a good dlc for those who enjoy UAV drones.Rest of them explain themselves in their names e.g. helicopter DLC adds some choppers that you can fly. You don't need DLC to be a passenger though.