Optional Armaments and Systems at JoiningThe following is a list of the optional armaments available to every EF and Zeon joinable mobile weapon (Rogues are taken on a case by case scenario.)
Officers who take non-Officer mobile suits are given an additional armament, noted in parenthesis.
Earth Federation 
Where weapons have a / sign (such as 90mm machinegun/100mm machinegun) the first option is taken by EFSF, and the second by EFGF. Note that fixed armaments are not listed, but any unit classifications such as (A), (S) or (D) are.
GM: Beam spray gun, 90mm machinegun/100mm machinegun, grenades, tower shield, bazooka (officers +gundam hammer/6 tube missile launcher)
GM Ground: 100mm machinegun, GM bazooka, 180mm cannon
(R), grenades, tower shield, arm shield (officers +gundam hammer)
GM Sniper (A): 100mm machinegun, GM bazooka, grenades, long range beam rifle
(A) (officers +6 tube missile launcher)
GM Cannon (A): Beam spray gun, 100mm machinegun, grenades, tower shield (officers +90mm machinegun w. grenade)
GM Aqua: 90mm waterproof machinegun, backpack missile launcher (officers +beam spray gun)
GM Diver: Beam spray gun, 90mm waterproof machinegun, grenades, tower shield (officers +arm shield)
GM Cold Climate Type: 90mm machinegun w. grenade, GM bazooka, grenades, shield (officers +180mm cannon
(A))
Guntank MPT (A): fixed grenade launchers (officers +fixed missile pods)
GM Desert Type: railgun
(A), 100mm machinegun, arm shield, grenades (officers +bazooka)
GM Land Combat Type: railgun
(A), 100mm machinegun, arm shield, grenades, beam spray (officers +bazooka)
GM E: 90mm machinegun, GM bazooka, grenades, tower shield (officers +beam spray gun)
GM Light Armor: Light beam rifle, 90mm machinegun, tower shield (officers +grenades & GM bazooka)
Zaku I B: 105mm machinegun, zaku bazooka, 90mm gm machinegun, tower shield, grenades (officers +luna titanium tower shield)
GM Command: Beam gun, 90mm machinegun/100mm machinegun, grenades, shield
Columbus: No Optional Armaments
Columbus B (R): No Optional Armaments
Salamis: Alternate Missile Options
GM Command Light Armor: Light beam rifle, 90mm machinegun, grenades, tower shield
GM Sniper Custom: Sniper Beam rifle, 100mm machinegun, beam pistol, grenades
Medea: No Optional Armaments
Medea B (R): No Optional Armaments
Hillock: Alternate Missile Options
Saberfish: alternate missile options
Saberfish II: alternate missile options
Type 61: fixed missile launcher
Tin Cod: alternate missile options
Fly Manta: +1 alternate missile hardpoint
Marines: anti foot equipment, anti armor equipment, Lakota
Core Booster: +1 alternate missile hardpoint
G Armor: No optional armaments
RX-78-1 (O): Gundam beam rifle, tower shield
GM Juggler (A): Beam gun, 90mm machinegun, full armor option, ball bits
(A)GM S Type: 100mm machinegun, GM bazooka, 6 tube missile launcher, grenades
GM Blue Destiny: 100mm machinegun, grenades, arm shield
Guncannon MPT: 100mm machinegun, beam spray gun, beam gun, beam rifle, grenades
Guncannon HDT: 100mm machinegun, beam spray gun, grenades
GM Sniper II: 90/100mm machinegun, ballistic sniper rifle
(A), beam rifle, bazooka, grenades, shield/arm shield, vulcan pack
SystemsGM Ground: Luna Titanium Armor
GM Sniper: Luna Titanium Armor
GM Cold Climate Type: Arctic Theatre Equipment
GM Sniper Custom: Advanced Targeting Visor
G-Armor: Docking Capability, Luna Titanium Armor
RX-78-1: Core Block, Re-Entry System, Luna Titanium Armor
GM Juggler: Psycommu
GM Desert: Reactive Armor, Desert Theatre Equipment
GMPGT: Luna Titanium Armor, Backpack Options
GM Blue Destiny: EXAM, Luna Titanium Armor
Guncannon HDT: Luna Titanium Armor
GM Sniper II: Advanced Targeting Visor
Duchy of Zeon 
Where weapons have a / sign (such as 90mm machinegun/100mm machinegun) the first option is taken by units that join in space, and the second by units that join on land. Note that fixed armaments are not listed.
Zaku I B: 105mm machinegun, zaku bazooka, leg missile pod, arm missile pod, heat hawk, grenades, puncher shield (officers +heat sword)
Zaku II F: 120mm machinegun, zaku bazooka, leg missile pod, sturm faust, heat hawk, grenades (officers +puncher shield)
Zaku II J (A): 120mm machinegun, zaku bazooka, leg missile pod, magella attack cannon
(A), heat hawk, grenades (officers +puncher shield)
Gouf: Zaku bazooka, heat sword, grenades, shield (officers +mmp-80)
Gogg: Freeze yard rounds
Zaku II HMT: 120mm machinegun, zaku bazooka, panzer fausts, heat hawk (officers +mmp-80)
Zaku II D: 120mm machinegun, 290mm missile launcher, leg missile pods, heat hawk, grenades, jetskis (officers +puncher shield)
Zaku II K (A): 120mm machinegun, zaku bazooka, leg missile pod, arm missile pod, grenades (officers +heat hawk)
Dom: Giant bazooka, heat saber, sturm fausts (officers +mmp-80)
Magella: fixed missile launcher
Dopp: wire guided missiles
Gunship Heli: alternate missile options
Xamel: giant bazooka, mmp-80 (officers +mmp-80 w. grenade)
Zaku II R2 HMT: 120mm machinegun, zaku bazooka, panzer fausts, heat hawk (officers +mmp-80)
Zaku II E (D): 120mm machinegun, grenades, fuel cells, shield (officers +zaku bazooka)
Rick Dom: giant bazooka, heat saber, sturm fausts (officers +mmp-80)
Gattle: alternate missile options
Marine: anti infantry equipment, anti armor equipment, Weasel
Zaku Minelayer: 120mm machinegun, zaku bazooka, heat hawk, grenades, minelaying equipment (officers +puncher shield)
Acquy (S): Freeze yard round, alternate arms
Panzergrenadier: anti infantry equipment, anti armor equipment, Wappa
Zaku Kai: mmp80g, zaku bazooka, heat hawk, grenades, (officers +leg missile pod)
Gouf Custom: arm gatling, heat sword, gatling shield (officers +zaku bazooka)
Zaku I S: 105mm machinegun, zaku bazooka, raketen bazooka, leg missile pods, arm missile pods, heat hawk, grenades, puncher shield
Zaku II S: 120mm machinegun, mmp-80, zaku bazooka, leg missile pod, sturm fausts, heat hawk, grenades
Dom S: beam bazooka, heat saber, sturm fausts, mmp-80
Zaku I Sniper (A): 105mm machinegun, zaku bazooka, heat hawk, beam sniper rifle
(A)Z'Gok: Freeze yard rounds
Dowadge: 120mm machinegun, 290mm missile launcher, heat tomahawk, sturm fausts, grenades
Musai (O): Alternate missile options
Papua (R): No optional armaments
Gallop: No optional armaments
Jukon: Alternate torpedo options
Zaku II Manipulator Type: 120mm machinegun, mmp-80, zaku bazooka, heat hawk
Zaku II Psycommu Test Type: No optional armaments
Braw Bro: No optional armaments
Dom Psycommu Test Type: Giant bazooka, mmp-80 w. grenade, heat saber
Dom Tropical Test Type: Giant bazooka, mmp-80 w. grenade, panzer fausts, heat saber
Gouf High Maneuverability Type: 120mm machinegun, zaku bazooka, shotgun, chain mine, heat sword, grenades, shield
Efreet: Shotgun, heat sword
Grabro: No optional armaments
Adzam: No optional armaments
Hildolfr (A): Alternate cannon rounds
Zock (L): No optional armaments
Zudah: 120mm machinegun, mmp-80, zaku bazooka, panzer fausts, heat hawk, grenades, puncher shield
Bigro: No optional armaments
Zakrello: No optional armaments
Val Varo: No optional armaments
Proto Gelgoog: Gundam beam rifle, mmp-80 w. grenade, heat saber, shield
Zaku II Minovski Particle Scattering Type (S): 120mm machinegun, heat hawk, sturm fausts, grenades
Apsalas I (O): No optional armaments
Gouf Flight Type: gatling shield, heat sword, mmp-80 w. grenade
Gouf Heavyarms: leg missile pod, arm missile pod, arm gatling pod
Action Zaku: 120mm machinegun, beam rifle, heat hawk, leg missile pod, sturm faust
Pezun Dowadge: giant bazooka, heat saber, panzer faust, mmp80+grenade, grenades
SystemsZaku II D: Desert Theatre Equipment
Magella: Escape Mechanism
Gouf Custom: Beam Resistant Coating
Zaku II Manipulator: Psycommu
Zaku II Psycommu Test Type: Psycommu
Braw Bro: Psycommu, Escape Mechanism
Dom Psycommu Test Type: Psycommu
Dom Tropical Test Type: Desert Theatre Equipment, Tropical Theatre Equipment
Zaku II Minovski Particle Scattering Type: M-Particle Scattering Eqiupment
Adzam: M-Craft
Apsalas I: M-Craft