My list was getting too long... Continuing!
Just for clarification, I'm intentionally only giving basic ideas for weapon damage. I don't want the weapons to be absurdly powerful... I would like for Obsidian to consider some of these after all. Despite how unlikely that is.
9mm Tactical SMG - Based on the MP530, 9mm magazine
Reflex Sight
Three round burst
High DPS/Moderate DAM
Special: +5% Accuracy
Two Hand
The big daddy of the SMG collection. It makes use of the 9mm cartridge for late game much like the Marksman Carbine does for the 5.56mm round. MP5's are accurate as all getout too hence the accuracy bonus.
Edit: Andaius beat me to the SMG category.
The Suppressor - Based on the M6050, .308 magazine
Iron Sights
Automatic
High DAM/High DPS
Two Hand
The big brother of the Light Machinegun, this monster fires a larger round from a belt-fed magazine. Designed to keep the enemy's head down in a firefight, just make sure you're watching your ammo because it'll go quick.
Edited: M60 it is! Just for you, Andaius!
Concussion Rifle5, Energy Cell magazine
Night Scope, x1 magnification
Single shot
High DAM/ Low DPS
Two Hand
A new addition to the Energy Weapons family, this weapon is designed to compress the air between the user and the target causing massive internal trauma on impact. Think of it as an explosion, minus the exploding part. The shockwave is what kills.
Stealth Carbine - Based on the G36K30, 5.56mm magazine
2.5x magnification scope
Three round burst
Moderate DAM/Moderate DPS
Two Hand
Silenced
Laser Dot
This German creation was designed for the soldier in mind. Made of lightweight polymer parts with a built-in scope, silencer, and laser aiming dot; any fairly trained person can be deadly with this weapon. The only downside is the lessened damage compared to other firearms of this caliber. Of course, the silencer would help you get a drop on your target so there would be less to worry about.
Edit: Thanks for the reminder about the Perferator, I Do Not Know!