There are a vast amount of weapons available in Rare's Goldeneye for the Nintendo 64. The majority of them are based on real weapons, usually very closely to the point that if they were given the actual guns' names, there would be no disputing their accuracy in context, considering that the game is not necessarily very strict with regard to realism. A few of the smaller weapons can be doubled up, with one in each hand. This can sometimes be realistic, such as in the case of the various pistols, but when it gets to submachine guns this is more for gameplay reasons than realism.
Most guns (nearly all pistols and submachine guns) in Goldeneye take one kind of ammunition, most likely intended to be some kind of 9mm pistol shell, though not all the real weapons these guns are based on take the same kind of ammo. If I don't note what kind of in-game ammunition a weapon takes, it uses the standard pistol bullets.
PP7 - Based on the Walther PPK, Bond's current weapon of choice in the films. Small-capacity semiautomatic pistol (7-round clip), available in the game with or without a silencer. Can be doubled.
DD44 Dostovei - Based on the Tokarev TT-33, a mid-20th-century Soviet weapon that's mediocre in most ways except durability. 8-round clip. Can be doubled.
Klobb - Since it is supposed to be the Czech-built Model 61 Skorpion machine pistol, the Klobb was originally going to be called the Spyder. However, it was renamed as a nod to Nintendo of America's Ken Lobb. Bond apparantly eschews the weapon's wire stock (shown in the game folded over the top of the weapon) and the game replicates the way the Skorpion "sprays bullets around in a very alarming fashion"1 - it's easily Goldeneye's least accurate weapon. 20-round clip (there are also 10-round clips for the real Skorpion, though there aren't in the game); can be doubled.
KF7 Soviet - Based on some type of Kalashnikov, either the AK-47 or AK-74; it's hard to tell which from the game. Automatic assault rifle; 30-round clip. Takes the same kind of ammo as the AR33, though the weapons they are based on do not. Apparantly has some kind of invisible telescopic sight - there is no scope visible on the gun, but one's view slightly zooms in when aiming. I think this is an acceptable concession of reality to gameplay, though.
ZMG 9MM - It's hard to tell what this is supposed to be. Possibly an Uzi, an Ingram MAC-10, or any of a great variety of similar-looking submachine guns, though it doesn't look exactly like any of them. The name isn't a clue, as it seems to just be a variant on "SMG" coupled with the size of its ammunition. 32-round clip, which makes it most likely to represent the Uzi, which has clips available in that capacity; can be doubled.
D5K Deutsche - Based on Heckler & Koch's MP5. Excellent submachine gun; 30-round clip; available silenced in Goldeneye and in real life. Can be doubled up in the game, though this would be a dodgy prospect in real life, it seems rather too big to carry one on each arm like Bond does.
Phantom - A strange, boxy submachine gun based on the Italian Spectre. 50-round clip; can be doubled. Its purpose in the game is ambiguous - it is effectively a D5K Deutsche with a larger magazine capacity, and is only found in a level where the "Deutsche" is already available.
AR33 Assault Rifle - Based on the M-16 or AR-15, the iconic, Armalite-built assault rifle that has been in use by the U.S. military in various incarnations since Vietnam. For some reason, in Goldeneye, this influential and recognizable weapon is functionally identical to the KF7 Soviet. 30-round clip, takes the same bullets as the KF7, and has the same invisible scope. It only looks like an Armalite because that would be a more appropriate weapon to find in certain settings than an AK.
RC-P90 - based on Fabrique Nationale's P90, this is a small, rapid-fire weapon that is bizarre and futuristic in appearance. 80-round clip - the actual P90 only has a 50-round clip, which is still quite large for a submachine gun.
Automatic Shotgun - Most similar to Franchi's SPAS, this weapon is more or less imaginary. I mention the SPAS for comparison, though, because it is similarly large, and is a semi-auto shotgun that, like Goldeneye's, looks like a pump shotgun, unlike others that are more similar in shape to an assault rifle or a submachine gun. But the SPAS has a seven-shot clip, and the Automatic Shotgun holds five shells. It has its own type of ammunition, and fires a spread of five pellets, each of which is as powerful as the game's standard smg/pistol round. Thus, it gains power, but loses range and accuracy, much like an actual shotgun.
Sniper Rifle - Another fairly generic, fabricated weapon, it nonetheless resembles some real-life rifles, though it could be derived from almost any sniper rifle that's shaped like an assault rifle. Takes the same ammunition as the KF7 and AR33; 8-round clip; is the only weapon in the game to have a telescopic sight that can be zoomed in and out, and the only weapon with a sight on which the sight is actually visible.
Cougar Magnum - Most likely based on the Colt Python, though that connection is based on name as much as appearance, this is a .357 magnum revolver, the sort made famous by the likes of Harry Callahan and Travis Bickle. Six-shot capacity; has its own ammunition. Its bullets penetrate glass and some doors.
The Golden Gun - This is the weapon Scaramanga wielded in The Man With The Golden Gun. Since he "only needs one (shot), with his Golden Gun", as asserted in that film's theme, the Gun in the game can kill any character with one shot (except Baron Samedi, Live And Let Die's voodoo priest who appears in the Egyptian Temple level, who is rather unkillable and absorbs quite a few golden bullets). It has a one-shot clip, and is slow to reload. It takes its own unique ammunition.
Laser - A hand-held laser pistol like the ones in the film Moonraker, this weapon has infinite ammunition and fires through glass and some doors. Besides those two advantages, it's a fairly bland weapon, with moderate rate of fire and damage. It's only found in the Aztec Temple level, and you'd be better off taking on Jaws with another weapon. But it's just so cool to be firing those blue laser bolts!
Watch Laser - This only counts as a weapon because it can hurt enemies. It's essentially a narrative device; it's similar to the Moonraker laser, but with a shorter range, and is available only in one level of the game, where it's used to break open a steel hatch at the end.
Grenade Launcher - Based on the MGL, made by Armscor, which is distinguished by its enormous revolver-style rotary magazine. Metal Gear Solid 2 led me astray on this one, breaking its trend of accurate names for real weapons by labelling its MGL-like grenade launcher "RGB-6", which doesn't refer to any weapon I know of2. Fortunately, Frank Castle set me straight on this one. Anyway, Goldeneye's Grenade Launcher holds six rounds, like the MGL, and uses its own type of ammunition.
Rocket Launcher - Basically a generic surface-to-surface or surface-to-air rocket. Entirely a "dumb" weapon; it has no target lock-on nor heat tracking, unlike many real man-portable rocket launchers. My best guess is that it's based on some kind of RPG (the Soviet rocket-propelled grenade kind, not the dungeons and monsters kind). It holds one round at a time, but reloading is quicker than you'd think for a rocket launcher.
Grenade - This is a hand grenade, probably not based on any real-life model of such. Hold the trigger button to pull the pin, release it to throw. The fuse is somewhere between three and five seconds. Unique ammo - not the same as the Grenade Launcher's grenades, of course.
Mines - These are not especially related to any real-world device, although the appearence of all three are based on the timed explosives that James Bond sets at the beginning of the film, a circle with four squared-off clamps spaced around its perimeter, and a small screen in the center with buttons under it. They come in three varieties: Timed Mines are essentially like hand grenades that stick to whatever surface you throw them at, Remote Mines are detonated at any time either by switching to the "detonator" weapon and pressing the trigger button or by pressing the A and B buttons simultaneously (this is a very useful trick), and Proximity Mines activate a few seconds after being thrown and then won't detonate until a character comes within a certain distance of them. All three can be manually detonated by shooting them.
Tank Gun - This weapon is only accessible in the game while driving a tank, as it's the tank's main gun. It is essentially like the Rocket Launcher, except that it is slower reloading, and the arc of the projectile's flight decays fairly rapidly, while the Rocket Launcher's missiles' arcs don't seem to decay at all.
There are a few weapons that don't really bear discussing, as there isn't much to them. "Unarmed" is simply a chop or slap delivered with Bond's bare hand, and does little damage. Certain weapons (the only one I can remember is the Sniper Rifle, but I believe there are others) replace the bare hand with the rifle's butt, which is slightly stronger. Throwing Knives are exactly what they sound like, and are used like the hand grenades - hold the weapon button to cock Bond's arm back, and release to throw. They're quite difficult to aim, but can be very deadly when aimed well.
There are also a few devices that aren't weapons at all, but are selected and used in the same way as weapons, such as tracking bugs and optical disks. There's little to say about them; they're usually either so generic as to be unable to be commented on, or entirely fictional, and their use is usually limited to "stand in right place, press trigger button".
Now, once one unlocks the All Weapons cheat option, all bets are off. With it activated, any weapon can be accessed at any time, and all can be doubled up. It also unlocks a number of weapons that were either cut from the game proper or not intended to be used at certain points - The Hunting Knife is essentially Unarmed, but with the strength of a bullet. The Shotgun is the same as the Automatic Shotgun, but it's pump-action. The Gold PP7 is a recolored PP7, with the one-shot kill ability of The Golden Gun. The Silver PP7 is not quite as strong as either Golden Gun, but is far stronger than any of the standard weapons. The Taser, whimsically labelled "Taser Boy", is a weapon that was originally intended to be used for knocking out guards without permanent damage or the attention-getting of gunfire, but it was never fully implemented, so the developers hacked together a Taser that fires invisible bullets and does damage as a fun bonus. All Weapons also allows Bond to use his Watch Laser in any stage, and makes the Tank Gun accessible without driving a tank. I like to imagine that Bond's firing the tank shells out of his mouth.
Footnotes and References:
1: Quote from A Directory Of The World's Weapons, copyright 1996 Marshall Cavendish and Aerospace Publishing, which was invaluable in identifying a few of these weapons, with its excellent line-art of guns and lists of magazine capacities and such.
Other sources include Nintendo Power magazine and Goldeneye-related promotional materials Nintendo sent me a few years ago, both copyright Nintendo at various dates, and comic book The Punisher's Armory, copyright 1993-1994 Marvel Entertainment Group.
Thanks to the above, to GameFAQs.com for making sure I didn't miss any weapons, and to my friend Ryoma Edanoshi for some weapons identification help. (not his real name, but a name indubitably his, and probably the username he'd use if he used E2 :)
2: If anyone does know of a real-life "RGB-6", or another grenade launcher with a rotary magazine like the MGL, tell me. I'm fond of this weird-looking weapon. I've even got a little 3 3/4"-G.I. Joe-sized version of it.
I was considering adding information on the game's multiplayer levels, and on the varying weapon sets available in multiplayer, but that seemed more like tedious transcription than anything interesting. At some point in the future I will probably compare the game's levels with the environments they represent in the film, but right now it's been too long since I saw the film. Anyone else is invited to write up any of that.