Depends how much you're willing to pay and what kind of game you're looking for. Do you want a huge skirmish in a cool place, an objective-based game or an actual milsim?
As event organisers, you have:
- Lion Claws (skirmish) - https://www.facebook.com/operationlionclaws
- Blacksheep (skirmish) - https://www.facebook.com/BlacksheepMilSim
- American Milsim (objective-based) - https://www.facebook.com/AmericanMilSim
- RAPTAC (milsim) - https://www.facebook.com/RaptorTacti...sandOperations
- MilsimWest (milsim) - https://www.facebook.com/MilSimWest
There are a few others, but these are the biggest. Some of them call themselves milsim cause it's the cool thing to do. I won't get into that debate here, this is merely my personal classification
. To really have a better idea of the playing style watch videos, read their rules etc.
Milsim West has traditionnally - as the name implies - been based out West (Washington state and neighboring states, mostly) but they've been expanding in the East with a game planned in Georgia and more coming eastwards. I'll be perfectly honest: MSW would be the only ones I'd personally travel that much for.
Blacksheep has recently been caught in a kind of scandal. Essentially, they advertised their thing as an event to help PTSD'd veterans, but it really was just a marketing ploy. Their recent event has been largely boycotted as a result and they're on the decline, and part of their paid staff decided to quit over that. Keep that in mind if you want to attend one of their events.