A game from my list for a tradable Borderlands 2:
GIFTS:
Ace of Spades
Alan Wake Franchise (Alan Wake CE + American Nightmare)
Alice Madness Returns
Angry Birds Space
Anna Extedned Edition
Assassin's Creed 2 Deluxe
Assassin's Creed Brotherhood Deluxe
Audiosurf
Baldur's Gate Enhanced
Bastion
Batman Arkham Asylum GOTY
Batman Arkham City GOTY
Battlefield Bad Company 2
Ben & Dan Double Pack (2 games)
Binary Domain
Bionic Commando Pack (2 games)
Bioshock 1
Bioshock 2
Blur (collectible game, no longer sold on Steam)
Book of Unwritten Tales Collection (Tales + Critter + Extras)
Borderlands GOTY
Breath of Death VII
Bully
Burnout Paradise Ultimate Box
Castle Crashers
Chantelise
Chaos on Deponia
Chivalry Medieval Warfare
Civilization 4 Complete
Civilization V
Clive Barker's Jericho
Command & Conquer 3 Tiberium Wars + C&C3 Kane's Wrath
Counter Strike 1.6 + Condition Zero
Counter Strike Source + Garry's Mod
Counter Strike Global Offensive
Critter Crunch
Dead Island GOTY
Dead Space 1
Dead Space 2
Defender's Quest
Defense Grid Containment Bundle (game and all DLC including Containment)
Deus Ex HR
Devil May Cry 3+4 Bundle
DiRT3
Dishonored The Knife of Dunwall DLC
Dungeon Defenders
Dungeon Siege Complete (1+2+3+DLC)
Europa Universalis 3 Chronicles
Europa Universalis Rome Gold (2 games)
Fable the Lost Chapters
Fable 3
Fallout 3 GOTY
Fallout New Vegas Ultimate
Fallout Collection (1+2+Tactics)
Forge
Fortune Summoners
From Dust
Frozen Synapse
Frozen Synapse Complete Pack
FTL
Galactic Civilizations 2 Ultimate Edition
Galactic Civilizations Complete Pack (2 games)
Garry's Mod
God Mode
Gothic Universe Edition (1+2+3)
Hotline Miami
Interstellar Marines
Just Cause 1
Just Cause 2
Killing Floor Bundle (June 2013, 14 items)
Lara Croft and The Guardian of Light
Left 4 Dead 2
LEGO Lord of the Rings
Magic the Gathering 2013 Gold Bundle (MTG2013 + Expansion + All decks)
Magicka
Mark of the Ninja
Might & Magic Clash of Heroes
Nation Red
Natural Selection 2
Need For Speed Hot Pursuit
Need For Speed Shift
Need For Speed Underground
Nuclear Dawn
Payday the Heist
Penny Arcade 3
Portal 2
Puzzle Dimension
Puzzle Quest 2
RAGE
Ravaged
Rayman Origins
Recettear
Renegade Ops w/ DLCs Pack
Red Orchestra 2 GOTY
Red Orchestra 2 GOTY Deluxe
Resident Evil 5
Ridge Racer Unbounded Full Pack
Risen
Rome Total War Gold
Rollercoaster Tycoon 3 Deluxe
Sants Row The Third Full Package
Serious Sam 3 BFE Gold (includes expansion & digital extras)
Scribblenauts Unlimited
Sim City 4 Deluxe
Sega & Sonic All Star Racing Transformed
Sonic Adventure 2 w/ Battle DLC
Sonic Generations
Spore
Star Wars KOTOR 2
STALKER Shadow of Chernobyl
Starvoid
System Shock 2
Terraria
Test Drive Unlimited 2
The Heroes Pack (HOMM V, Hammers of Fate, Tribes of the East, Dark Messiah)
The Polynomial
The Showdown Effect
The Testament of Sherlock Holmes
The Walking Dead
The Witcher 1 Enhanced Edition
The Witcher 2 Enhanced Edition
Titan's Quest Gold (2 games)
Tomb Raider Anniversary
Tomb Raider Legend
Tomb Raider Underworld
Torchlight 2
Tropico 4 Collectors Bundle
Two Worlds 2 Velvet Edition
Unreal Tournament 2004
Viking Battle for Asgard
Warhammer 40K Dawn of War Retribution
STEAM KEYS:
GT Legends
Blood Bowl Legendary Edition
Crazy Taxi
Jet Set Radio
SEGA Bass Fishing
Sonic Adventure DX
Space Channel 5
A New Beginning
Alan Wake CE
Alan Wake American Nightmare
Air Buccaneers
Avernum Bundle
Awesomenauts
Bastion
Bioshock 1
Bioshock 2
Brutal Legend
Company of Heroes Tales of Valor (standalone)
Costume Quest
Darksiders
Duke Nukem Forever
Galaxy on Fire 2 HD
Iron Brigade
Killing Floor Bundle (Oct 2102, 12 items)
La Mulana
Mark of the Ninja
Might & Magic Clash of Heroes + I am the Boss DLC
Psychonauts
Red Faction Armageddon + Path to War DLC
Red Orchestra 1 + 2 GOTY
RUSE
Spec Ops the Line
Stacking
Supreme Commander 2
Toy Soldiers
Warhammer 40,000 Space Marine
Adventures of Shuggy
Alien Hallway
Alien Shooter Revisited
Anomaly Warzone Earth
Atom Zombie Smasher
Aquanox 1
Aquanox 2
Aquaria
Avadon the Black Fortress
Avencast
Basement Collection
Beat Hazard Complete
Binding of Isaac + Wrath of Lamb
The Blackwell Bundle
Brazen Prototype
Capsized
Cargo Commander
Cave Story Plus
Chrome + Specforce
Cogs
Closure
Crash Time 2
Crayon Physics Deluxe
Crusader Kings 1 Complete
Cryostasis (not in Steam store)
Dead Hungry Diner
Dear Esther
Death to Spies Moment of Truth
Death Track
DEFCON
Dino D-Day
Doc Clock
Droplitz
Dynamite Jack
Dungeons the Dark Lord
Eets
Edna & Harvey
English Country Tune
Eschalon Book 2
Faerie Solitaire
Fairy Boom Freesia
Fantasy Wars
Fractal
Galactic Arms Race (not in Steam store)
Geneforge Saga 1-5
Gettysburg Armored Warfare
Grotesque Tactics
Grotesque Tactics 2
Gumboy
Hacker Evolution Untold
Hearts of Iron 3
iBomber Defense Pacific
Insecticide
Indie Game the Movie
Intrusion 2
Karateka
King's Bounty the Legend
Kung Fu Strike
Little Inferno
Madballs in Babo + DLC
McPixel
Memento Mori
Men of War
Men of War Red Tide
Men of War Vietnam
Men of War Assault Squad DLC Pack
Multiwinia
Necrovision
Necrovision Lost Company
Nightsky HD
Offspring Fling
Oil Rush + DLC
Organ Trail
Pacific Storm Allies
Painkiller Black
Painkiller Overdose
Party of Sin
Patrician 4 Gold
Pirates of the Black Cove
Planets Under Attack
Post Apocalyptic Mayhem
Post Mortem
Primordia
Puzzle Bots
Reign: Confict of Nations
Robin Hood Legend of Sherwood
Rig n' Roll
RIP Trilogy
Section 8
Scratches
Shadowgrounds
Shadowgrounds Survivor
Shank 1
Shank 2
Shattered Horizon
Slam Bolt Scrappers
Snapshot
Solar 2
Spellforce Platinum
Splice
Star Ruler
Star Wolves 3
Stealth Bastard Deluxe
Still Life
Still Life 2
Stellar Impact
Superbrothers Sword & Sworcery EP
Sword of the Stars 1 Complete
Sword of the Stars 2 Enhanced
Swords & Soldiers HD
Syberia
Syberia 2
The Journey Down
Thomas Was Alone
Tropico Trilogy
Tiny & Big Grandpa's Leftovers
Titan Quest
Tobe's Vertical Adventure
Vessel
Victoria 2
Warhammer Dawn of War 1 GOTY
Warlock Master of the Arcane
Waking Mars
Weird Worlds Return to Infinite Space
X-Blades
XII Century Gold
Zen Bound 2
Zeno Clash
Zombie Shooter 1
Zombie Shooter 2
HIB3 Android 3 Bonus key (World of Goo, Anomaly, Osmos, EDGE)
Looking for Games, Cards with equal value