Some informations with links to promotional DLC's in case someone might be missing out.http://www.darksiders.com/promotions
1: Argul's Tomb (It was included in all new copies of the game before the official launch for free, also avaible on Steam store) - Storyhttp://community.darksiders.com/tombhttp://store.steampowered.com/app/215825
2: Crucible Arena (Included in all copies of the game) - Story
3: Crow Hammer (Prima Official eGuide, also avaible on the Steam store) - Weaponhttp://community.darksiders.com/crowhammerhttp://store.steampowered.com/app/215819
4: Mace Maximus (Pre-order august 28th, also avaible on the Steam store) - Weapon http://community.darksiders.com/mace
5: Mortis (Pre-Order Abomination Vault July 24th, also avaible on Steam store) - Weaponhttp://community.darksiders.com/mortishttp://store.steampowered.com/app/215816
6: Dark Talons (Pre-Order) - Weapon
7: Skeletal Axe of Rending (Pre-Order) - Weapon
8: Angel of Death Pack (Best Buy Pre-Order, also avaible on Steam store) - Weaponhttp://store.steampowered.com/app/215813
9: Deadly Despair Pack (Amazon Pre-Order, also avaible on Steam store) - Weaponhttp://store.steampowered.com/app/215814
10: Death Rides Pack (Gamestop Pre-Order, also avaible on Steam store) - Weaponhttp://store.steampowered.com/app/215812
1: Pauldron Of The Horseman (Darksiders 1 completed) - Weapon
(Level 5 Legendary Armor): Unlocked for playing Darksiders 1. Boosts stats and critical damage.
2: Chaos Fang Scythe (Darksiders 1 completed) - Weapon
(Level 1 Legendary Scythe): Unlocked for completing Darksiders 1 on any difficulty. Boosts damage and critical damage.
---Note: Only saved achievements/trophies from Darksiders 1 on the same device will unlock gear in Darksiders 2.
3: Rusanov's Axe (Facebook app, expired on August 21st, also avaible on Steam store) - Weaponhttp://store.steampowered.com/app/215817
4: Van der Schmash (Account linking from in-game) - Weaponhttp://community.darksiders.com/register http://community.darksiders.com/soulharvest
5: Darksiders 1 (EA Origin Digital Deluxe version)
Season Pass: http://store.steampowered.com/app/215824
1: Maker's Armor & Scythe (Screenshot ingame below) - Weapon + Armorhttp://steamcommunity.com/sharedfiles/filedetails/?id=94815179
2: The Abyssal Forge Pack - Storyhttp://store.steampowered.com/app/215826
3: The Lord Demon Belial - Storyhttp://store.steampowered.com/app/215827
If you see any error/something i missed feel free to pm me on the forums or post here, and i will make sure to check it out.