Base Weapon: Shotgun/Energy Weapon Combo
Name: Force-O-Nature
Appearance: A double, quad, or even maybe quint*-barreled shotgun, with varied energy weapon looking tubes, knobs, etc. coming off the barrels.
Stats: It fires standard shotgun shells, but when fired it imparts a random energy to the shot, like fire, electricity, plasma and so forth. Because of this it degrades extremely fast.

Base Weapon: Shotgun
Name: "In Lead We Trust" (working title)
Appearance: A large, single barreled 4 gauge** shotgun, very old looking
Stats: It fires shotgun shells unique to itself, or possibly 4 regular ones at a time or something funny like that. very high damage, has a chance to completely "bloody mess" enemies

Base Weapon: Grenade Launcher Ammo
Name: Beehive
Appearance: Like http://lh3.ggpht.com/_Z4ehflEmhuc/Smqa90XJUkI/AAAAAAAAA50/5isyVdJE8bo/s800/40mmBeehiveRound.jpg
Stats: This is a crafted weapon that requires 20 .22 shells, 1 tin can, 1 40mm grenade and some glue or something like that. When fired from the grenade launcher it fires a large number of .22 shells, somewhat like a shotgun. A "Wasp Nest" variant could fire several volleys before reloading.

Base Weapon: Combat Knife
Name: Gutmaster 3000
Appearance: A large, intimidating knife of some kind.
Stats: higher damage, has a chance to sever the limbs of non-dialogue targets without killing them.

Base Weapon: 9mm pistol
Name: Colt Operator Special, or something similarly tactical sounding
Appearance: Something like http://souzousha.deviantart.com/art/Souzousha-s-Colt-1911-160841177?q=gallery%3ASouzousha%2F23828716&qo=3. Remember to thank Souzousha over at deviant art for that gem.
Stats: Higher damage, more accurate at longer ranges, higher capacity, select fire capability (full auto, burst), acts as a grenade launcher as well

Base Weapon: Plasma Rifle
Name: The Hoover Blam!
Appearance: Mostly like the normal plasma rifle, but with a gray/bluish vibe and electrical arcing
Stats: Fires globs of electrified water that splash and are contagious, dealing damage over time to anything that they come into contact with, or that comes into contact with things that have come into contact with them.

Base Weapon: Landmine
Name: Clusterf**k
Appearance: like a landmine, but with a bunch of grenades taped to the top of it
Stats: This is a crafted weapon that requires 5 grenades, 1 landmine, and some duct tape. when the mine is triggered, it explodes at a regular mine, but sends the grenades out a ways, which then also explode in a wider area.
This would also have a bunch of variants for the different types of mines and grenades there are, like a Plasma Clusterf**k or a Pulse Clusterf**k.

That's enough for now, but I'll probably be back later if I think of anything else I like.

*that's 5 barrels, don't know if anyone's ever made such a thing, but sounds cool to me. If 4's good, 5's better, right?
**yes, they did exist. They used them for turkey hunting back in Ben Franklin times or something, I've seen a ye olde magazine ad for them. they shot 4 ~9mm pellets, can't imagine what a slug for something like that would be like if it existed.

dirty dan: a unique boxing glove with nails and barb wire sticking out of it deals lots of damage but slower punching rate

Base Weapon: .357 Magnum
Name:Shalashaska.
Appearance: PURPLE! And GREEN!
Stats: Has the ability to one-shot EVERYTHING in the Mojave Wasteland.

Nice Ideas man. I have always wondered what a hornet's nest grenade could do to a squad of raiders. The only type of weapon that has not been mentioned is booby traps. I don't mean something reminiscent of an Indiana Jones movie but a device like the traps of fo3. How fun would it be to see a raider activate a Rub Goldberg machine that would lead to his own demise.

I love everything but the purple...really. And one hit killing everything is pretty broken... Just make it to where you can hit anything. Like when Ocelot actually shot Fortune who was supposed to be invincible.... I would make it to where it ignores the DT.

Base Weapon: Predator Drone / Laser Designator
Name: Major King Kong (Slim Pickens character name in Dr. Strangelove)
Appearance: A tripod that has desert camo that paints the location to be bombed.
Stats: Predator can carry different payloads amounts like 10 frag missiles or 2 mini nukes. Takes awhile to setup. Can not re-load in the wasteland. You must go back to your base in reload the drone.

Raven: Base weapon: Minigun: Massively increased ROF, but that means it burns through ammo REALLY quickly, so you will end up reloading it often.

RPG(really powerful grenade): Base weapon: Frag grenade: These extremely rare explosives are comparable to Fo3's bottlecap mine in power, user beware, these svckers are heavy!(small throw range)

Round Pounder(get it?): Base weapon:Grenade machine gun: Grenades fired do extra damage with a direct hit, very little arc, slower fire rate and decreased mag. size.

Bulk Smash: Base weapon: Concrete sledge: This extra-large concrete sledge swings extra-slow and extra-hard. (Warning: People will dislike the user when he/she is angry)

Stars and Stripes: Base weapon: LMG: This red white and blue Mg is heavily modified with an extra large magazine and a shortened barrel and an increased ROF. Does less damage then normal LMG.(possibly plays the U.S. national anthem while firing, song resets when the weapon is reloaded.)

Base Weapon: Combat Knife
Name: #52 (in ode to Ray Lewis the greatest linebacker in football ever)
Appearance: Purple Camo
Stats: Does the same amount of damage as a regular CK but you can't get in trouble with the cops/locales for killing someone with it.

It would be hilarious if you cut a limb off a raider and they muttered something along the lines of "Tis' but a scratch" before charging at you yelling things like "I'll bite your legs off!", "Just a flesh wound!" and "I've had worse!"

Plasma Caster
Electro Blaster
The gun is very blue and silver metallic.
Electro Blaster fires away a lightning beam towards enemies, this lightning beam is extremely powerful and can chain travel if enemies are cluttered.
It also has a chance to stun enemies.
Problem is that it takes 100 electron charge package or 40 microfusion cells or 80 energy cells to fire one shot then it needs to reload.
Can be great at clearing out "horde" or "pack" enemies, worthless when against humans that are very far from each other.

So the one who created this weapon basically took the plasma caster and replaced it's plasma features with new stuff but it's shell is still that of a plasma caster and the model looks the same.

Base Weapon: Semi-auto rifle
Name: Spittoon
Effect: Higher crit damage and more item health. Magazine size reduced by 3 or 2. Lets off a PING! sound everytime when fire and of course when reloading.

Base Weapon: Bat
Name: Funny Bone
Appearance: Super mutant femur, painted yellow with red polka dots. corkscrews in the top painted red. Also character dons a clown nose when wielding.
Effect: High chance to disarm enemies( you know, because it svcks when you get hit in the funny bone), also chance character laughs uncontrollably after a kill.

Base Weapon:357 Magnum
name: martson sidearm/magnum
Appearance: soild Gold
Stats: faster reload and increases amount of "money"(as there more that one ) on people kill by it

http://fallout.wikia.com/wiki/Slasher_Knife

AND

This

Base Weapon: Super Sledge
Name: The Thunder Hammer
Appearance: The handle is brownish and creates electricity
Stats: Very high damage with with electric damage and maybe stun.

my 2nd weapon idea
base weapon: a rolled up flag (could be all around unique, only flag you can bash a guys skull in with in the game)
name: till' they see stars
appearence: a rolled up flag that has a ripper wonderglued to the top that you can slash them with.
discription: a little weaker than a sledge but stronger than a ripper.

"My Little Friend" - a 4 shot http://en.wikipedia.org/wiki/Derringer gun that hides in your sleeve when you "holster" it and extends from your sleeve with an arm mechanism when it is un-holstered. Useful as a "holdout" weapon for the New Vegas casinos...

Here's a "movie prop" build of one:

http://www.wonderhowto.com/how-to-make-quick-draw-sleeve-gun-from-taxi-driver-272184/

Base Weapon: Weapon Mod
Name: haven't thought of one yet.
Appearance: A little scaffold arm that attaches to the muzzle of a gun with a little electrified loop on the end of it.
Stats: When attached to a gun, this mod electrifies (or plasmafies, or laserfies, whatever is best) the bullets that are fired as they pass through the loop, adding additional elemental damage.

Base Weapon: .357 Revolver
Name: Judge (or something that alludes to that, if theres a copyright problem or anything)
Appearance: Same as base, maybe a different color (blued or something)
Stats: This gun has been rechambered in .45LC/.410, and as such, can be loaded with regular .45 bullets or shotgun shells. it degrades faster when firing shotgun shells because the pellets get caught in the rifling.

I want to be able to build (with a schematic) a "Fraghammer". It is a Super Sledge with a mine attached to the front. It explodes on impact. It has 2 ammo requrments in order to use. It does the damge of the Mine comined with the damage of the Super Sledge. You must have frag mines, wonderglue so that you can replace the mine. As far as a skin difference goes, it should look burnt.

Build requrments: Frag Mine, Super Sledge, Wonderglue.

Sorry it's not in the correct format, but I posted this somewhere else, and didn't want to change it up too much.

Dont mean to criticize but wouldnt it be Jupiter not Zeus do to it being Roman.
Here is one.
Jupiter's Sting: A Gladius style blade connected to a car battery, the car battery would be located on your hip, deals electric damage, you can see blue and white bolts of electricity warping around the blade.

I had an idea like that awhile ago. Great Idea

But, the 9mm Pistol is a Browning Hi-Power not a Colt M1911
Here:
Base Weapon: 9mm Pistol, Unique mod.
Name: Colt .45 Conversion Kit.
Effect: Changes the 9mm Pistol to a .45 Pistol, also changing the skin to that of a Colt M1911, that way we don't have to have two extremely similar looking guns, we just have a mod! Possibly located in a old armory.

Base Weapon: Knife
Name: Assassin's Claw
Skin: Dagger, similar to the http://en.wikipedia.org/wiki/File:Fairburnsykes_colour4.jpg], black grip and handle, silvery blade with etchings.
Effect: Unique Stealth Attack (if there are any at all), Sneak Attack Critical increase, higher damage.

Hrm sounds like a Pepperbox Derringer, of which there were multiple varients with anything up to seven barrels.

Base weapon: shotgun
Name: Grandpa's revenge
Skin: double barrel pump action like http://www.thefirearmsforum.com/attachment.php?attachmentid=27826&stc=1&d=1248014292.
Effect: Holds 16 shells and has a high powered shot, has to pump every 2 shots, and has a painfully long reload time.
http://www.youtube.com/watch?v=gNNWLIED4bI

I would like to see Pa's Fighing Aid, The Cyronator