If a majority are capable of preferring their own private interest, or that of their families, counties, and party, to that of the nation collectively, some provision must be made in the constitution, in favor of justice, to compel all to respect the common right, the public good, the universal law, in preference to all private and partial considerations... And that the desires of the majority of the people are often for injustice and inhumanity against the minority, is demonstrated by every page of history...

Well, last I heard Mass Drivers (previously Flaylocks) and explosives in general rule competitive matches (PC). That and Shotguns I guess.

With that said, they're about to introduce two new ARs, the Rail Rifle and Combat Rifle, so of course this game will be centered around the soon to be four kinds of ARs.

The only primary weapons are the ARs, Mass Driver, Shotgun, Sniper, Laser and HMG (for anti-infantry use)

Mass Driver is present in PC matches.
Shotgun is also present.
Sniper is present and has a role in PC matches.
HMG is present, but since the role of the heavy sucks, it's not really that useful.
Laser, well it's the Laser, so meh.
Then there's the currently two kind of ARs, which are obviously used a fair bit. This is soon going to be four kind of ARs.

There's also two heavy weapons coming at some point, one of those being pure anti-infantry (supposedly) and the other both AV and AI. There's a shorter ranged sniper of some kind coming at some point as well.