[Senkusha]

I found the following list on Reddit while searching for games that use a Standard Deck of Playing Cards.  I've decided to add this listing because there are some places where dice are not permitted, and cards make an easy substitution.

Games that use playing cards as a Core mechanic

• 52 Fates
• And You Will Rest Your Head on Your Parent's Grave
• Angakkuit
• Aesir: The Last Avatar
• Back to the Beginning
• Beat to Quarters
• C22 System
• Capers
• Castle Falkenstein
• Crash Cart
• Cold Dead Hands
• A Cool and Lonely Courage
• Delve
• Dog Bear
• Draw: A Simple Western
• Dust Devils
• Duty & Honour
• Exile Deal
• EXUVIAE
• FAITH
• Frankenstein Atomic Frontier
• Generations
• Grin
• Gun & Slinger
• Hands of Destiny
• Heaven & Earth
• Hillfolk
• The House Doesn't Always Win
• Hot Guys Making Out
• In a Wicked Age
• The King is Dead
• Legends of Avallen
• Love & Barbed Wire
• Merger
• Miserable Secrets
• mole.mole
• Monkey: The Roleplaying Game
• Motobushido
• Murderous Ghosts
• My Way
• Network 23
• Night Reign
• Nine Worlds
• Our Minerva
• Parselings
• Praxis Arcanum
• Primetime Adventures
• Protocol Game Series
• Purgatory House
• The Quiet Year
• Rascals
• Route Clearance
• Saga Machine system (Shadows Over Sol, Against the Dark Yogi, Dime Adventures and Age of Ambition)
• Shonen Final Burst
• Suited
• The Suits
• Tadhana: A Filipino Tabletop RPG
• Terra the Gunslinger
• Through the Breach
• Tokyo NOVA
• Unbound
• UNOwned (uses an Uno deck)
• Upwind
• We Are Champion
• Westbound
• Wild Cards
• Wretched & Alone
• Zombie World

Games that use playing cards in some aspect of the mechanics (or as an option)

• Aces & Eights
• All Flesh Must Be Eaten
• Blue Rose (Tarot)
• Deadlands
• Deliria
• Dream Askew
• FATE
• Forbidden Lands
• The Ground Itself
• Journey
• Never Going Home
• Savage Worlds
• Sleepaway
• Steampunkers
• Twilight: 2000
• Wolsung

Games that use Tarot Cards

• 7th Sea 1e & 2nd Edition
• Alas Vegas
• Anomaly
• Artesia
• Blade of Arcana
• This Body of Mine
• Demon City
• Engle
• Everway 2nd Edition
• Fate of the Norns
• Fortune's Fool
• His Majesty the Worm
• House of Cards
• Psychosis
• Relics
• Royal Blood
• Sine Requie
• Tarotweaver: A Tarot Based TTRPG
• Weave
• You Are the Dungeon

Games that use a proprietary card deck

• A Thousand Faces of Adventure
• The Brokenhearted
• Clockwork Dominion
• Dialect
• Dragonlance: Fifth Age
• Dungeon Solitaire: Labyrinth of Souls (Tarot)
• For the Queen
• Free Market
• Gamma World (7th Edition)
• Invisible Sun
• Juggernaut
• Marvel Super Heroes Adventure Game
• Mouse Guard
• Paranoia: Red Clearance Edition
• Phoenix: Dawn Command
• Sign
• Spindlewheel
• TORG
• Torg Eternity
• The Yellow King
• This Thing We Started
• Winterhorn 

I plan on enhancing this list with mini descriptions as I have time to add them.  Perhaps some of these games will end up as official library entries here on the site!