GTA V, like all GTA games before it, features a huge array of different weapons which are available for the player to use. Unlike in previous GTA games, however, weapons are accessed via a weapon wheel, which can accommodate every single weapon, even those of the same class/category, each of the protagonists comes across, as well as buy, in the game. Furthermore to this, regardless of whether you die (Wasted) or get arrested by the cops (Busted), weapons aren't lost. However your ammunition will be reduced to zero for all weapons upon being arrested. Each individual protagonist also has his own weapons.

Also available are a number of weapon modifications for each weapon, including silencers, magazine capacity upgrades, flashlights among other things.

Melee
Knife

Used for stabbing things. Also good for stealthy takedowns.

Hammer

Usually used for hitting nails into wood. In the world of GTA however, this is used as a melee weapon.

Crowbar

Nightstick

This weapon is favoured by security guards to subdue potential troublemakers. This can, however, also be brought in any Ammu-Nation gunstore.

Baseball Bat

Golf Club

Used for hitting golfballs around a golfcourse. However, if you persuade anyone at the golfclub they will surely lend you one, which you can use as a weapon.

Broken Bottle
The broken bottle is quite effective at delivering the appropriate message in up close and personal encounters. Available for free with the Beach Bum Pack.

Hand Guns
Pistol
A standard handgun. .45 caliber with a magazine capacity of 12 rounds that can be extended to 16.
Combat Pistol
A compact, lightweight, semi-automatic pistol designed for law enforcement and personal defence. Like the standard pistol, it has a magazine capacity of 12 rounds which can be extended to 16.

AP Pistol
A high-precision, fully-automatic pistol that holds 18 rounds with the option of extending to 36 rounds.
Stun Gun
A non-lethal weapon capable of temporary stunning a target. Despite it being a non-lethal weapon, however, two shots that land on any particular target will kill them. It has unlimited ammo, however takes around 4 seconds to recharge.
SNS Pistol
A small pistol; available for free with the Beach Bum content update.

Machine Guns
Micro SMG
Combines the compact design of a handgun with the high rate of fire and damage of a sub-machine gun.
SMG
A good all-round submachine gun featuring an accurate sight and a 30-round magazine capacity.
MG
General purpose machine gun that combines rugged design with dependable performance. This is a weapon that is good used at long range as well as when used against large groups.
Combat MG
Lightweight, compact machine gun that combines excellent manoeuvrability with a high rate of fire.

Assault Rifles
Assault Rifle

Carbine Rifle

Advanced Rifle


Sniper Rifles
Sniper Rifle

Heavy Sniper


Shotguns
Pump Shotgun

Sawed-Off Shotgun

Assault Shotgun


Heavy
Grenade Launcher
A grenade launcher capable of lobbing grenades over a longer distance then if you were to throw them. These grenades also tend to explode on impact. This is a weapon that is good when used against groups of enemies, and also good at scattering groups of enemies as well.
RPG
Got any pesky police helicopters following you? Use this piece of artillery to send them a message they won't soon forget. 
Minigun
Send your enemies an endless barrage of bullets with the minigun. Be mindful that when a character is using this weapon, they will walk considerably slower, making them vulnerable to flanking enemies.

Projectiles

Grenade

Jerry Can

Molotov

Sticky Bomb

Tear Gas