H: Ace of Spades, Castle of Illusion, Hotline Miami 1 & 2, Mount & Blade: Warband W:Games

Steam
Ace of Spades: Battle Builder - Steam Gift
Ahnayro
Alien Breed 2: Assault
Alien Breed 3: Descent
Anachronox
Anomaly: Warzone Earth (combined key with Osmos & EDGE)
ARMA: Gold Edition
Avalanche 2: Super Avalanche
Back to the Future: The Game
Beatbuddy: Tale of the Guardians
Bionic Commando: Rearmed
BioShock
Blockstorm
Braid (Combined key with Lone Survivor: The Director's Cut and Super Meat Boy)
Breath of Death VII
Broken Sword: Director's Cut
Broken Sword 2 - the Smoking Mirror: Remastered
Castle of Illusion
Chroma Squad
Contraption Maker
Cook, Serve, Delicious!
Cthulhu Saves the World
Dead Island: Game of the Year Edition
Dead Pixels - Steam Gift
Deadlight
Death Ray Manta SE
Doc Clock: The Toasted Sandwich of Time
Door Kickers
Double Dragon: Neon
Dwarfs!?
East India Company Gold
EDGE - Steam Gift
EDGE (combined key with Anomaly: Warzone Earth & Osmos)
Enforcer: Police Crime Action
Fate of the World
Fate of the World: Denial
Fate of the World: Extras Pack
Fate of the World: Migration
FEZ
Fish Fillets 2
Fortix 2
Fractal: Make Blooms Not War
Freedom Force vs. the Third Reich
Frozen Synapse
Frozen Synapse - Steam Gift
Frozen Synapse Prime - Steam Gift
Galak-Z
Gemini Rue
Giana Sisters: Twisted Dreams
Guacamelee! Gold Edition
Guns of Icarus Online - May Keep
Gun Monkey - Steam Gift
Heavy Bullets
Hexcells Complete
Home
Hotline Miami
Hotline Miami 2: Wrong Number
Infection: Humanity's Last Gasp
Ink
Insurgency
Intrusion 2 - Steam Gift
It came from space, and ate our brains
Killer is Dead - Nightmare Edition
Lead and Gold: Gangs of the Wild West
Lethal League
Lone Survivor: The Director's Cut (Combined key with Braid and Super Meat Boy)
LOST PLANET 3 Complete
Lovely Planet
Magicka
Monaco: What's Yours Is Mine
Mount & Blade: Warband - key should be good, but you should go first to be sure
Natural Selection 2
NightSky
Oddworld: Abe's Oddysee
Orcs Must Die!
Osmos (combined key with Anomaly: Warzone Earth and EDGE)
Outlast
Pixel Heroes: Byte & Magic
Poker Night 2
Poker Night at the Inventory
Prison Architect
Puzzle Agent
Ravensword: Shadowlands
Renegade Ops + all DLC - Steam Gift
Retro/Grade
Reus
RUSH - Steam Gift
Rush Bros. - key should be good, but you should go first to be sure
Sanctum
Savage Lands
Serious Sam HD: The Second Encounter - Steam Gift
Skullgirls + DLC
Skullgirls
Skulls of the Shogun
Sonic & All-Stars Racing Transformed
SpaceChem
Space Engineers
Spec Ops: The Line
SpeedRunners - May keep
Spelunky
STRIDER / ストライダー飛竜
Super 3-D Noah's Ark
Super Hexagon - Steam Gift
Super Meat Boy (Combined key with Braid and Lone Survivor: The Director's Cut)
SUPERFIGHT
Supraball
Surgeon Simulator - Anniversary Edition
Swords and Soldiers HD
The Binding of Isaac Collection (The Binding of Isaac + Binding of Isaac: Wrath of the Lamb)
The Bureau: XCOM Declassified
The Darkness II
The Deed - key should be good, but you should go first to be sure
The Dream Machine: Chapter 1 & 2
The Dream Machine: Chapter 3
The Dream Machine: Chapter 4
The Last Remnant
The Ship: Murder Party - Steam Gift
The Swapper
The Walking Dead
The Walking Dead: 400 Days
Thief Gold
Time Gentlemen, Please! and Ben There, Dan That! Special Edition Double Pack
Tiny and Big: Grandpa's Leftovers - Steam Gift
To the Moon
Toki Tori - Steam Gift
Toki Tori
Toki Tori 2+
Town of Salem
Velocibox
World of Goo
Year Walk
Zeno Clash

Nintendo 3DS
Gunman Clive
Mighty Switch Force!
Retro City Rampage: DX (3DS)

Most of the above Steam keys are giftable from Humble Bundle or IndieGala, but ask to be sure if that is a concern.