AN-94

 "In service with elite Russian forces, the AN-94 offers a unique, highly accurate, 2 round burst feature. Compared to the standard AK series, the AN-94 requires a significantly higher degree of training. A skilled shooter can effectively engage targets at a longer range than typical Assault Rifles." — Battlelog description

  

AN-94 is one of the most accurate assault rifles in Battlefield 3, due to its 2 round burst fire mode.

It fires 600 rounds per minute on full auto and staggering 1200 rpm in burst auto mode.

I personally like the M16 more then AK series, but this gun is  completely different. AK rifles have a lower accuracy and have a higher recoil, but this gun is good at long ranges and has more manageable recoil. This gun is a beast when using in long range maps like Caspian Border or Operation Firestorm, but you should use another gun in close quarter situations due to the low rpm auto fire and high recoil. My personal favourite attachments for the AN-94 are:

Kobra sight for fast ADS

Foregrip (you may want to use the bipod for longer range)

Laser sight for better hip fire accuracy.

Ratings for this weapon:

Accuracy: 4/5

RPM: 4/5

CQC: 2/5
Bullet damage: 3/5
Recoil: 4/5

Unlocks      

 PSO-1 (10 kills)
 Heavy Barrel (20 kills)

 Foregrip (30 kills) 

 Tactical Light (40 kills)

 Kobra (50 kills)

 Bipod (60 kills)

 Suppressor (70 kills)

 PKA-S (80 kills) 

 Laser Sight (90 kills) 

 IRNV (100 kills) 

 PKS-07 (125 kills)

 PK-A (150 kills)

 Flash Suppressor (175 kills)

 ACOG (200 kills)
 Reflex (235 kills) 

 Holographic (270 kills)
 Rifle Scope (300 kills)

 M145 (350 kills)