Best weapons by type?

[False Prophet]

Personally I'm a huge fan of the vindicator assult rifle. Black Widow sniper rifle, and geth shotgun. I dont use Heavy weps too much in compat but do save a couple cain rounds for oh ♥♥♥♥ moments.

[AbedsBrother]

Mattock rifle, Geth plasma shotgun, Viper sniper rifle, Phalanx Pistol, Arc Projector (heavy).

[QwibQwib]

Rifle: Mattock (but I like the Vindicator too)
Sniper: Widow
Shotgun: Geth
Pistol: Phalanx
SMG: Never use it but Locust for Shepard, Tempest for squad.
Heavy: I love using the Collector particle beam on Collectors as punishment. Arc Projector otherwise. I always take the Cain for the last mission!

[BloodyMares]

Pistol: Carnifex
SMG: Tempest or Locust (Kasumi DLC)
Shotgun: Claymore or Geth Plasma (DLC)
Assault Rifle: Vindicator or Mattock (DLC). Revenant would be awesome if it was a bit more accurate.
Sniper Rifle: Widow
Heavy: Cain. If you can handle it.

[The Extreme Potato]

IMO

Pistol: Arc Pistol. I love the charging function, it makes it a very versitile pistol. Put a scope on it and you have a pocket sniper rifle...

SMG: Locust. The zero recoil is extremely usefull and it has a solid DPS so can quicly take down sheilds.

Shotgun: Haven't really used them that much, so I'll have to go with what's best for squadmates. Which I think is the Gral Spike Thrower

Rifle: Saber. Semi-auto rifle with enough firepower to one-shot a Brute if you mod it right.

Sniper: Javelin. Again, with the charging function

Heavy Weapon: Blackstorm

[DocStrangelove]

Note: I don't have all the DLC weapons, for example no geth plasma shotgun

Rifles: Vindicator
Shotguns: Scimitar
Sniper rifles: haven't used them in ages, so can't tell
SMG: Tempest
Pistols: Carnifex
Heavy: Particle Beam

[Potato PC]

Depends what class i pick, but usually i only use vindicator assult rifle.