DwayneGAnd
Look, Ma! Two Heads!
I've already created a thread for the best armor in New Vegas. Now I will make one for the best weapons for endgame builds. Feel free to comment or post your own opinions.
Here, I choose weapons that are not only powerful, but are easy to maintain. Thanks to Jury Rigging, something which Fallout 3 could have benefitted from, it's easier to maintain many unique weapons and keep them in good shape. For guns, also choose those that have powerful ammo variants for all purposes including armor piercing bullets.
Guns
Antimaterial Rifle-The most powerful single shot scoped rifle. Great for taking out the toughest enemies in the game. However, the bullets are among the heaviest in the game on Hardcore mode. Great for high strength sharpshooters.
Gobi Campaign Scout Rifle-Another powerful scoped rifle. Good for medium strength sharpshooters. The built in repair kit keeps it in good shape and slows its decay.
Christine's Silencer Rifle-Perfect for stealthy characters thanks to the supressor.
Mysterious Magnum-For cowboys, it's the best sidearm that can be snuck into casinos. Hand loaded ammo is quite powerful and can punch through armor too.
Ranger Sequoia-The most powerful pistol in the guns category. However, it's easier to get if you're not on good terms with NCR.
Hunting Revolver-Great for sniping, even if the scope doesn't zoom as far as on scoped rifles. For cowboys who specialize in sneak attack criticals with the bonus from the Professional, this is a great choice as are the other two cowboy pistols above.
Trail Carbine-Once you add the scope, this is the best sniping weapon for cowboys when using handloaded ammo.
Medicine Stick-In terms of damage and durability, this is the best rifle for cowboys, especially when loaded with handloaded ammo.
Lever Action Shotgun-The only shotgun affected by cowboy.
L'il Devil-Though it requires more strength than other pistols, it has the highest damage per second of all pistols. Very powerful.
A Light Shining In the Darkness-The best sidearm for Grunts.
Riot Shotgun-The best shotgun in terms of damage and reloading speed.
Dinner Bell-If your strength isn't enough in the endgame to use Riot Shotgun, this is the best shotgun. It is also far more accurate than the Riot Shotgun.
This Machine-Great all purpose rifle in terms of damage and durability. Easy to get.
Avenger Minigun-The ultimate heavyweight gun. 5mm ammo that is handloaded is great for taking out heavily armored foes and deathclaws.
Assault Carbine-Great for lightweight grunts due to the 5mm handloaded ammo being able to penetrate armor.
Survivalist's Rifle-Great all purpose semi-automatic weapon. 12.7mm ammo of course is rarer than other types of ammo.
All American-Sniper weapon of choice of grunts.
12.7mm SMG-The best SMG in the game.
FIDO-Great alternative to the Avenger due to the fact that it comes with a scope for sniping. Also helps alert you to danger and nearby enemies.
Energy Weapons
Pew Pew-Best energy weapon sidearm in the game in terms of damage. However, it uses a lot of ammo per shot and can degrade quickly if using max charge ammo.
YCS/186-Great sniping weapon in Energy Weapons category. Do not take Wild Wasteland however as the ammo for the Alien Blaster is limited. The fact that it needs to be reloaded after every shot is a drawback, but unlike the Gauss Rifle in Fallout 3, it is much easier to maintain yourself.
Cleansing Flame-The best medium to close range weapon for pyromaniacs in terms of damage. The optimized ammo created by Vigilant Recycler can penetrate armor better.
Sprtel-This variant of the gatling laser is the best choice for high strength energy sharpshooters. Power and durable. Laser Commander makes this a death machine.
Smitty Special-Power Single shot plasma rifle. Need high strength to use it though.
Sonic Emitter Tarantula-Great sidearm for pyromaniacs.
LAER-Great for medium length combat, at least until fully modded. Multiple beams make it more ideal for close range. Elijah's variant remains good for long range even when fully modded.
Matter Modulator-Great variant of the plasma rifle due to higher durability and damage.
Multiplas Rifle-Great for close range.
Tri-beam Laser Rifle-Same as Mutliplas Rifle, but becomes more powerful with Laser Commander.
Qua
Melee Weapons
Ballistic Fist-The best unarmed weapon in the game for damage. Need high strength to use it of course.
Industrial Hand-Powerful and durable, it also ignores damage threshold, the only weapon in the unarmed category than can do so.
Thermic Lance-The most powerful melee weapon in terms of damage and its ability to ignore damage threshold.
Chainsaw-Same as the Thermic Lance with its ability to ignore damage threshold. When fully modded, it becomes lighter than the Thermic Lance.
Oh Baby-The most powerful blunt melee weapon. Cannot ignore damage threshold of course.
Explosive
Mercy-Great for heavyweights due to being automatic. Getting it is quite difficult because of its location and the deathclaws that inhabit it. Heave Ho! makes the grenades travel farther. Great for crowd control. Demolition Expert makes it even more powerful. Make sure you take Hit the Deck and Splash Damage both to protect yourself and for a bigger explosion radius.
Annabelle-Good to use as a longe range attack for melee characters.
Red Glare-Same as Annabelle, but comes with a scope.
Frag Grenades-For lower strength characters who use explosives as a secondary attack. More common than Plasma Grenades. More powerful with Demolition Expert.
Plasma Grenades-More powerful than Frag Grenades, just not as common.
Here, I choose weapons that are not only powerful, but are easy to maintain. Thanks to Jury Rigging, something which Fallout 3 could have benefitted from, it's easier to maintain many unique weapons and keep them in good shape. For guns, also choose those that have powerful ammo variants for all purposes including armor piercing bullets.
Guns
Antimaterial Rifle-The most powerful single shot scoped rifle. Great for taking out the toughest enemies in the game. However, the bullets are among the heaviest in the game on Hardcore mode. Great for high strength sharpshooters.
Gobi Campaign Scout Rifle-Another powerful scoped rifle. Good for medium strength sharpshooters. The built in repair kit keeps it in good shape and slows its decay.
Christine's Silencer Rifle-Perfect for stealthy characters thanks to the supressor.
Mysterious Magnum-For cowboys, it's the best sidearm that can be snuck into casinos. Hand loaded ammo is quite powerful and can punch through armor too.
Ranger Sequoia-The most powerful pistol in the guns category. However, it's easier to get if you're not on good terms with NCR.
Hunting Revolver-Great for sniping, even if the scope doesn't zoom as far as on scoped rifles. For cowboys who specialize in sneak attack criticals with the bonus from the Professional, this is a great choice as are the other two cowboy pistols above.
Trail Carbine-Once you add the scope, this is the best sniping weapon for cowboys when using handloaded ammo.
Medicine Stick-In terms of damage and durability, this is the best rifle for cowboys, especially when loaded with handloaded ammo.
Lever Action Shotgun-The only shotgun affected by cowboy.
L'il Devil-Though it requires more strength than other pistols, it has the highest damage per second of all pistols. Very powerful.
A Light Shining In the Darkness-The best sidearm for Grunts.
Riot Shotgun-The best shotgun in terms of damage and reloading speed.
Dinner Bell-If your strength isn't enough in the endgame to use Riot Shotgun, this is the best shotgun. It is also far more accurate than the Riot Shotgun.
This Machine-Great all purpose rifle in terms of damage and durability. Easy to get.
Avenger Minigun-The ultimate heavyweight gun. 5mm ammo that is handloaded is great for taking out heavily armored foes and deathclaws.
Assault Carbine-Great for lightweight grunts due to the 5mm handloaded ammo being able to penetrate armor.
Survivalist's Rifle-Great all purpose semi-automatic weapon. 12.7mm ammo of course is rarer than other types of ammo.
All American-Sniper weapon of choice of grunts.
12.7mm SMG-The best SMG in the game.
FIDO-Great alternative to the Avenger due to the fact that it comes with a scope for sniping. Also helps alert you to danger and nearby enemies.
Energy Weapons
Pew Pew-Best energy weapon sidearm in the game in terms of damage. However, it uses a lot of ammo per shot and can degrade quickly if using max charge ammo.
YCS/186-Great sniping weapon in Energy Weapons category. Do not take Wild Wasteland however as the ammo for the Alien Blaster is limited. The fact that it needs to be reloaded after every shot is a drawback, but unlike the Gauss Rifle in Fallout 3, it is much easier to maintain yourself.
Cleansing Flame-The best medium to close range weapon for pyromaniacs in terms of damage. The optimized ammo created by Vigilant Recycler can penetrate armor better.
Sprtel-This variant of the gatling laser is the best choice for high strength energy sharpshooters. Power and durable. Laser Commander makes this a death machine.
Smitty Special-Power Single shot plasma rifle. Need high strength to use it though.
Sonic Emitter Tarantula-Great sidearm for pyromaniacs.
LAER-Great for medium length combat, at least until fully modded. Multiple beams make it more ideal for close range. Elijah's variant remains good for long range even when fully modded.
Matter Modulator-Great variant of the plasma rifle due to higher durability and damage.
Multiplas Rifle-Great for close range.
Tri-beam Laser Rifle-Same as Mutliplas Rifle, but becomes more powerful with Laser Commander.
Qua
Melee Weapons
Ballistic Fist-The best unarmed weapon in the game for damage. Need high strength to use it of course.
Industrial Hand-Powerful and durable, it also ignores damage threshold, the only weapon in the unarmed category than can do so.
Thermic Lance-The most powerful melee weapon in terms of damage and its ability to ignore damage threshold.
Chainsaw-Same as the Thermic Lance with its ability to ignore damage threshold. When fully modded, it becomes lighter than the Thermic Lance.
Oh Baby-The most powerful blunt melee weapon. Cannot ignore damage threshold of course.
Explosive
Mercy-Great for heavyweights due to being automatic. Getting it is quite difficult because of its location and the deathclaws that inhabit it. Heave Ho! makes the grenades travel farther. Great for crowd control. Demolition Expert makes it even more powerful. Make sure you take Hit the Deck and Splash Damage both to protect yourself and for a bigger explosion radius.
Annabelle-Good to use as a longe range attack for melee characters.
Red Glare-Same as Annabelle, but comes with a scope.
Frag Grenades-For lower strength characters who use explosives as a secondary attack. More common than Plasma Grenades. More powerful with Demolition Expert.
Plasma Grenades-More powerful than Frag Grenades, just not as common.