What is the best gun in deus ex human revolution

Some of the guns considered to be the best are:
10mm Pistol - This is very powerful and very accurate when upgraded with laser sight and armor piercing. It can take down heavy soldiers with one shot to the head.

Revolver - When you upgrade the revolver to have explosive ammo this is very powerful and can rip through large groups of enemies.

Combat Rifle - This is also very powerful when upgraded. If you have laser sight and flechette rounds it is very accurate and strong, which helps in boss fights.

PEPS - If you are doing a non-lethal playthrough this is very helpful but even if you aren't it can knock down large groups of enemies and give you time to get to cover or throw a grenade.