Ok, so there are reputedly about 1000 Loyalist SM chapters out there in the Imperium doing their thing, so I thought it'd be cool to see what we can come up with here. (This has been done before, but this time I was thinking you could post names/fluff/pictures to make it more complete.) I will put up 'official' GW chapters etc (again feel free to add your pictures of your marines) but please add your homebrew chapters, I want to see how complete we can get here 
THIS IS LOYALIST ONLY
Ok to kick off the game: The First Founding
Dark Angels
White Scars
Space Wolves
Imperial Fists
Blood Angels
Iron Hands
Ultramarines
Salamanders
Raven Guard
Ok.
Following these were the Second Founding Chapters:
Grey Knights
Dark Angels Successors:
Angels of Absolution
Angels of Redemption
Angels of Vengeance
Blood Angels Successors:
Angels Encarmine
Angels Sanguine
Angels Vermillion
Blood Drinkers
Flesh Tearers
Spoiler
Honour's End: 837.M41: During the Eclipse WARS, the Space Wolves fight alongside the Angels Vindicant and Flesh Tearers Chapters upon the shrine world Lucid Prime. Largely due to a ferocious Flesh Tearers counter-attack, Imperial forces are able to drive off the Chaos Space Marine forces terrorising Hive Ratspire. However, the Flesh Tearers continue their indiscriminate killing even after the Chaos renegades have been driven away. Despite Chapter Master Seth's inisistence that his men are purging those that have been tainted by the presence of Chaos, the Space Wolves are outraged and attack the Flesh Tearers at once. The resultant battle sees brother fighting, with the death of many hundreds on either side. This terrible event is known forever more as Honour's End.
(Space Wolf Codex, pg.19)
The Knights of Blood
Ultramarines Successors:
Aurora Chapter
Black Consuls
Doom Eagles
Eagle Warriors
Genesis Chapter
Inceptors
Libators
Mortifactors
Nemesis
Novamarines
Patriarchs of Ulixis
Praetors of Orpheus
Silver Eagles
White Consuls
Raven Guard Successors:
Black Guard
Raptors
Revilers
Imperial Fists Successors:
Black Templars
Crimson Fists
Soul Drinkers
Iron Hands Successors:
Brazen Claws
Red Talons
White Scars Successors:
Destroyers
Marauders
Rampagers
Storm Lords
Space Wolves Successors:
Wolf Brothers
Twenty First Founding - Cursed - Founding:
Black Dragons
Fire Hawks = Legion of the Damned
Lamenters
Flame Falcons
Minotaurs
Sons of Antaeus
Later Foundings:
Angels of Fire
Angels of Iron
Angels of Vigilance
Angels Porphyr
Angels Vindicant
Astral Knights
Avenging Sons
Black Dragons
Black Wings
Blood Ravens
Blood Swords
Brazen Minotaurs
Brotherhood of a Thousand
Celebrants
Celestial Lions
Consecrators
Crimson Guard
Dark Crusaders
Dark Eagles
Dark Hands
Dark Hunters
Dark Sons
Death Eagles
Death Knights
Death Spectres
Death Strike
Disciple of Caliban
Doom Eagles
Doom Legion
Doom Warriors
Emperor's Hands
Emperor's Hawks
Emperor's Spears
Emperor's Swords
Emperor's Warbringer
Excoriators
Executioners
Exorcists
Fire Angels
Fire Lords
Flame Eagles
Flesh Eaters
Golden Gryphons
Grey Slayers
Grief Bringers
Guardians of the Covenant
Halo Dragons
Hammers of Dorn
Harbingers
Hawk Lords
Howling Griffons
Imperial Castellans
Imperial Harbingers
Imperial Hawks
Imperial Paladins
Imperial Stars
Imperial Talons
Invaders
Iron Champions
Iron Fists
Iron Hearts
Iron Knights
Iron Lords
Iron Snakes
Knights of Gryphonne
Knights of the Raven
Lion Warriors
Mantis Warriors
Marines Errant
Marines Exemplar
Marines Malevolent
Masters of Protelus
Mentor Legion
Metamarines
Night Hawks
Night Watch
Omega Marines
Rainbow Warriors
Reclaimers
Red Hunters
Red Legion
Red Scorpions
Red Templars
Red Wolves
Relictors
Sable Swords
Scythes of the Emperor
Silver Skulls
Skull Bearers
Sons of Gulliman
Sons of Medusa
Sons of Orar
Space Sharks
Star Dragons
Star Phantoms
Star Scorpions
Steel Confessors
Storm Callers
Storm Giants
Storm Hawks
Storm Wardens
Storm Warriors
Storm Wings
Subjugators
Tauran
Tigers Argent
Valedictors
War Bearers
Warmongers
Warrior Adepts
White Minotaurs
White Panthers
White Templars
Other Chapters:
Deathwatch
Spoiler
Deathwatch members are primarily volunteers from Space Marine chapters that rigidly adhere to the Codex Astartes. Because teams are made up of battle brothers from several Chapters, it is essential they follow a similar doctrine. On the Eastern Fringe of the Imperium, the Inquisitorial Fortress at Talasa Prime has recruited, trained and equipped Kill-teams from the Ultramarines, Scythes of the Emperor and Lamenters Chapters for service against the Tryanids. Even though they are recruited from among a wide variety of Chapters, these battle brothers put aside all Chapter disputes and grievances to fight alongside their new brothers for a common cause. As such, it's not uncommon to find Space Wolves and Dark Angels battle brothers in the same Kill Team for example, each one as willing to die for the other as if they were of their own Chapter.
Very often, these Space Marine volunteers will complete their tour of duty in a Death Watch Kill Team and return to their Chapter, where they are given the right to wear the Deathwatch shoulder pad on their left shoulder in place of their normal armour plate. Their right shoulder plate bears their Chapter heraldry at all times.
Deathwatch Kill Teams consist of a high proportion of Veterans and are often led by Space Marine Captains, though they will on occasion be led by Space Marine Librarians.
Courtesy of edmundblack
Absolvers
Adulators
Angels of Damnation
Angels of Fury
Angels of Penance
Angels of Purgatory
Angels of Repentance
Angels of Retribution
Angels Penitent
Angels Redeemed
Angels Repentant
Angels Resplendant
Angels Revenant
Avengers
Benedictors
Black Inculpators
Black Talons
Blood Legion
Brazen Skulls
Contenders
Crimson Castellans
Crimson Paladins
Crusaders
Dark Brotherhood
Desert Lions
Dictators
Dragon Lords
Emperor's Storm
Espandors
Exoriators
Excubants
Execrators
Exemplars
Golden Halos
Halo Dragons
Heralds of Vengeance
Hospitallers
Hounds of Demos
Interceptors
Inculcators
Inceptors
Invictors
Inviolators
Iron Crusaders
Knights of Eternity
Liberators
Libators
Legion of Night
Marines Errantor
Oblators
Panthers
Penitents
Purgators
Ravagers
Reclaimers
Redeemed
Redeemers
Redemptors
Red Wings
Reparators
Retractors
Rhetors
Silver Guard
Sky Sentinels
Star Leopards
Stone Hearts
Supplicators
Tarantulas
Tempestors
Tormented
Tormentors
Tributors
Venerators
Venerators of Osiron
Victors
Vindicators
Warhawks
Warriors Tempest
Widowmakers
(240 Chapters to this point)
Other sighted Chapters:
Sons of Aran
Bladed Angels
Midnight Angels
The Brothers of the Blooded Wolves
Angry Marines
The Emperor's Pointy Sticks
Sons of Scion
Terranus Sky
Pretty Marines
Adeptus Orthodontus
Disco Marines
Lazy Marines
Manly Marines
Reasonable Marines
Scary Marines
Sleepy Marines
Ebon Drakes
Storm Sons
Kerberos Chapter
Cosmic Space Knights (of Doom)
Flamebearers
Shadow Knights
Arctic Templars
Danish Space Marines
The Emperor's Vengeance
The Lazaruses
Saints of Vengeance
Sons Of Lucifer
Red Wolves
Teria Warriors
The Hell Forgers
Red Dragons
Spoiler
Red Dragons Space marine Chapter - The Red dragons call hel their home, but prefer the northern mountains to the lush jungle. The marked distinction of the Red dragons from other companies is that the first stage of the transformation must be earned by rite, like the space wolves. The initiates are trained by veterans of the chapter and taken to mount Nidhogg, there they must find, fight, subdue and tame, but not kill a northern drake. This task is incredibly difficult as it is much more difficult to tame the Northern Drakes than it is to tame the Eastern Drakes, and one or two may have to be killed before one can be found that can be tamed. Nothern drakes differ from their eastern kin used by the Imperial regiments in that they are slightly smaller, heavier and more robust with out the ability to fly, with large diamond hard teeth. After which they are allowed to drink, with their new pet drake, from the chalice of hellfire, at which time The skin of the initiates turn a copper to red color and hardens, the eyes of the red dragons then turn gold. Unlike the space wolves however they share no risk in becoming a beast themselves, although a few exhibit a more drastic reaction than others which causes the betchlers gland to no longer produce a poison or acid but a highly flammable liquid, similar to promethium that ignites on contact with air, allowing them to actually breathe fire. Weather they gain the ability to breathe fire or not, the drinking from the Chalice of Hellfire, permanently bonds the Marine and the Drake.
Astral Lupine Chapter
Lost Crusaders
The Forgotten
Fire Tenants
Sanguine Brotherhood
Ice Wolfs
Son's Of Odin
Spoiler
Originally Posted by Reece Thompson
My Chapter (Homebrewed)
Name: Sons of Odin
Primarch: Odin
Home World: Kyron Prime (Destroyed) Now live on a series of Ships
Picture:
Odin was the first Primarch made by the Emperor. More like a brother than a son. When the Emperor started work on the other primarchs, Odin left to forge his own world. Things went smoothly, then the Horus Heresy set the world alight. A large chaos fleet came to Kyron Prime and set the world alight, making it unhabitable for hundreds of millenium. Odin refused to fight and he took his civilisation outside the known galaxy where they were safe. Eventually, they returned to the galaxy, and Odin discovered that the primarchs wree dead and his brother was gravely injured. He made a pact with the council of terra that all record of his Chapter be expunged, they never existed, but Odin swore to help the Imperium. Chaos has to pay. The Sons of Odin do not believe the Emperor is a god, they are not part of the Imperium, but they do work with them. Like mercenaries.
Warcry: For Odin and the Emperor.
Sons of Setmini
The Heralds of Truth
Spoiler
Page 5 for fluff - Morr
Knights Penitent
Spoiler
Page 5 for fluff - SierraHotel
Iron Dragons
Spoiler
Page 5 for fluff - Gendoikari87
Space Reavers/Warp Reavers (conflicting Imperial reports)
Spoiler
Page 5 for fluff - Void Lord
Hellhounds
Spoiler
Page 5 for fluff - herplover
Royal Falcons
Spoiler
Page 6 for fluff - Ramseh
Obsidian Guard
White Hands
Spoiler
Page 6 for fluff (both) - Andy (!)
White Blight
Iron Wolves
Sons of Bale
Tears of Terra
Emperor's Dragon
Jagannatha
Avenging Angels
Spoiler
Page 6 for fluff (all 5)
Iron Dragons
Cleansing Flames
Filli Sangui
Brotherhood of the Hooded Brothers
Spoiler
Page7-8 for fluff
Chained Espadas
Teria Warriors
The Sentinels
Eagle's Vengeance