Humble Bundle is having a Spring sale which includes rotating flash sales and other long-term deals
I recommend using Ctrl+F (Cmd+F on Mac) to search for a couple of letters in the title since there are so many.
List of bargains at the moment (prices in USD):
Flash Sales:
Batman Arkham Origins: $7.49 from $29.99 (Expires 11AM). EXPIRED, no new deal yet.
Octodad: Dadliest Catch: $7.49 from $14.99 (Expires 3PM? Originally appeared to be listed as 11AM)
Long-term Deals:
Batman Arkham Origins $8.99 from $29.99 - Was $7.49 in Flash Sale
Sonic Hits Collection: $7.49 from $29.99
South Park Stick of Truth: $37.32 from $55.99
Towerfall Ascention: $11.99 from $14.99
Walking Dead Season 2: $16.66 from $29.99
Outlast: $4.99 from $19.99
Kerbal Space Program: $16.19 from $26.99
Thief: $24.99 from $49.99
Shadowrun Returns: $4.99 from $14.99
Shadowrun Dragonfall: $9.99 from $14.99
Broken Age: $14.99 from $24.99
Blade Symphony: $7.49 from $14.99
Metro Last Light Complete: $13.32 from $19.99
Nidhogg: $9.99 from $14.99
Walking Dead 400 Days: $1.24 from $4.99
Age of Empires 3 Complete: $13.99 from $39.99
Papers, Please; $6.66 from $9.99
Auditorium: $1.39 from $6.99
Age of Empires 2 HD: $9.99 from $19.99
FTL Faster Than Light: $7.99 from $9.99
Sir, You Are Being Hunted: $16.99 from $19.99
Prison Architect Alpha: $19.79 from $29.99
Trine: $0.99 from $9.99
Halo: Spartan Assault $3.74 from $4.99
Hotline Miami: $4.99 from $9.99
Kentucky Route Zero: $18.74 from $24.99
Eldritch: $5.99 from $14.99
Godus: $9.99 from $19.99
Trine 2: $3.99 from $19.99
Euro Truck Sim 2: $12.49 from $24.99
System Shock 2: $3.99 from $9.99
Rogue Legacy: $7.49 from $14.99
Mortal Kombat Komplete Edition: $9.99 from $19.99
Pixeljunk Shooter: $2.24 from $8.99
Antichamber: $9.99 from $19.99
AVGN Adventures: $7.49 from $14.99
Guns of Icarus Online: $3.74 from $14.99
Chivalry Medieval Warfare: $9.99 from $24.99
Space Hulk: $14.99 from $29.99
Stick it to the Man!: $5.99 from $14.99
Dungeon Defenders: $24.99 from $49.99
Game Dev Tycoon: $7.99 from $9.99
Don't Starve Reign of Giants DLC: $4.49 from $4.99
Castle Story Beta: $14.99 from $19.99
Scribblenauts Unmasked: $9.99 from $19.99
Continue?987653210: $4.99 from $9.99
Dear Esther: $3.33 from $9.99
Risk of Rain: $6.89 from $9.99
Mercenary Kings: $13.32 from $19.99
Cook, Serve, Delicious!: $6.99 from $9.99
Scourge: Outbreak Ambrosia Bundle: $4.49 from $8.99
Commandos Collection: $3.24 from $12.99
Metro 2033: $7.49 from $14.99
The Novelist: $7.49 from $14.99
Amneisa: A Machine for Pigs: $13.32 from $19.99
LUFTRAUSERS: $8.99 from $9.99 (Amazing Discount!)
DLC Quest: $0.99 from $2.99
Gone Home: $13.32 from $19.99
Project Zomboid: $13.49 from $14.99
The Bridge: $2.99 from $9.99
Hammerwatch: $3.99 from $7.99
LIMBO: $4.99 from $9.99
Dust: An Elysian Tale: $7.49 (If you don't have it already through XBLA or Humble)
Evoland: $4.99 from $9.99
Out There: $1.99 from $3.99
Deadly 30: $1.24 from $4.99
Braid: $5.99 from $9.99
Bridge Constructor: $2.49 from $9.99
Natural Selection 2: $8.33 from $24.99
Gnomoria: $3.99 from $7.99
Divekick: $4.99 from $9.99
The Inner World: $4.99 from $14.99
Shank 2: $4.99 from $9.99
Psychonauts: $4.99 from $9.99
Pixeljunk Monsters Ultimate: $2.49 from $9.99
Bardbarian: $2.44 from $6.99
CastleStorm Complete: $7.49 from $14.99
Killing Floor: $9.99 from $19.99
Race the Sun: $6.99 from $9.99
Brutal Legend: $9.99 from $14.99
SteamWorld Dig: $6.66 from $9.99
Botanicula: $3.49 from $9.99
Tesla Effect: A Tex Murphy Adventure: $17.99 from $19.99
Legend of Grimrock: $7.49 from $14.99
Surgeon Simulator 2013: $4.99 from $9.99
Beat Hazard Ultra: $6.49 from $12.99
Full Mojo Rampage: $9.74 from $12.99
Lilly Looking Through: $3.99 from $9.99
KickBeat: $4.99 from $9.99
King's Bounty Collector's Pack: $29.14 from $54.99
Meridian: New World: $11.96 from $14.95
Volgarr the Viking: $7.79 from $11.99
QuestRun: $3.59 from $8.99
Fallen Enchantress: Legendary Heroes: $19.99 from $39.99
Worms Reloaded & Worms 2: Armageddon: $9.99 from $19.99
Card City Nights: $1.99 from $3.99
Retro City Rampage: $3.99 from $9.99
MirrorMoon EP: $5.99 from $9.99
Dungeon Hearts: $0.74 from $2.99
Awesomenauts: $4.99 from $9.99
Guacamelee! Gold Edition: $7.49 from $14.99
Foul Play: $5.99 from $14.99
Machinarium: $3.49 from $9.99
Monaco: What's Yours Is Mine: $7.49 from $14.99
Retro/Grade: $2.49 from $9.99
Hero Siege: $4.99 from $9.99
Capsized: $2.49 from $9.99
Ironclad Tactics: $9.99 from $14.99
Murdered Soul Suspect (Preorder): $44.99 from $49.99
Ittle Dew: $6.99 from $13.99
Fronzen Synapse: $12.49 from $24.99
Shadow Warrior: $15.99 from $39.99
A Wizard's Lizard: $11.24 from $14.99
Probably Archery: $4.99 from $9.99
140: $3.32 from $4.99
Draw a Stickman: EPIC: $2.49 from $4.99
Saints Row: The Third - Full: $14.99 from $29.99
Darksiders II: $14.99 from $29.99
Saints Row IV Season Pass: $4.99 from $9.99
Kingdom Rush: $4.99 from $9.99
UnEpic: $8.49 from $9.99
Our Darker Purpose: $9.99 from $14.99
Deponia: $6.99 from $19.99
Survivor Squad: $4.04 from $8.99
Supreme Commander Gold Edition: $9.99 from $19.99
Post Master: $7.47 from $14.95
ArcaniA & Gothic Bundle: $24.99 from $49.99
Attractio: $4.99 from $9.99
PixelJunk Eden: $2.49 from $9.99
Doorways Chapter 1 and 2: $4.99 from $9.99
Incredipede: $4.99 from $9.99
Dominique Pamplemousse: $3.49 from $4.99
The Guild II: $4.99 from $9.99
Super Hexagon: $1.99 from $2.99
Legend of Dungeon: $6.99 from $9.99
Rising Storm: $9.99 from $19.99
ReignMakr: $9.99 from $14.99
Saints Row IV: $29.99 from $39.99
Anomaly 2: $7.49 from $14.99
Magicka Collection: $20.99 from $34.99
FORCED: $9.99 from $14.99
Steam Marines: $5.99 from $9.99
Pulse: Volume One: $1.49 from $2.99
Back to the Future: The Game: $18.74 from $24.99
Intake: $2.49 from $4.99
Galactic Civilizations II: Ultimate Edition: $9.99 from $19.99
FOTONICA: $4.99 from $9.99
Fractal: $3.49 from $6.99
Titan Quest Gold: $9.99 from $19.99
Space Pirates and Zombies (S.P.A.Z) $4.99 from $9.99
Cube and Star: An Arbitrary Love: $3.49 from $6.99
Sins of a Solar Empire: Rebellion: $19.99
Splice: $4.99 from $9.99
Beatbuddy: $3.99 from $9.99
Shadowgrounds: $1.39 from $6.99
Sniper Elite V2: $19.99 from $29.99
Aqua Kitty: Milk Mine Defender; $4.89 from $6.99
rymdkapsel $7.19 from $7.99
The Floor is Jelly: $8.49 from $9.99
MouseCraft: $11.99 from $14.99
The Showdown Effect: $5.99 from $9.99
Solar Flux: $4.99 from $9.99
Paper Dungeons: $12.74 form $14.99
Strike Suit Zero: $13.32 from $19.99
Samorost2: $1.74 from $4.99
Hearts of Iron III: $5.99 from $9.99
Orcs Must Die 2 Complete: $12.49 from $24.99
Shadowgrounds Survivor: $1.99 from $9.99
Offspring Fling: $3.99 from $7.99
Waking Mars: $3.99 from $9.99
Ironclad Tactics: Blood and Ironclads: $3.32 from $4.99
Cubetractor: $4.49 from $9.99
Super Splatters: $4.99 from $9.99
Vessel: $7.49 from $14.99
King Arthur's Gold: $7.49 from $9.99
Kinetic Void: $13.32 from $19.99
Darksiders: $9.99
Tower of Guns: $9.74 from $14.99
Rehearsals and Returns: $1.99 from $3.99
Windosill: $1.49 from $2.99
Amnesia: The Dark Descent: $11.99 from $19.99
Last Knight: Rogue Rider Edition: $4.49 from $5.99
Solar 2: $4.99 from $9.99
FIST OF AWESOME: $1.49 from $1.99
Eets Munchies: $4.66 from $6.99
Ironclad Tactics: The Rise of Dmitry: $3.32 from $4.99
Metro Last Light Season Pass: $7.49 from $14.99
Puzzle Agent: $3.74 from $4.99
Poker Night at the Inventory: $3.74 from $4.99
Tetrobot and Co: $6.99 from $9.99
Anodyne: $5.99 from $9.99
Delve Deeper: $2.49 from $4.99
Puzzle Agent 2: $7.49 from $9.99
Luxuria Superbia: $5.59 from $6.99
Raensword: Shadowlands: $9.99 from $14.99
Hive: $7.99 from $9.99
Power-Up: $2.24 from $2.99
Blocks That Matter: $3.74 from $4.99
Hack, Slash, Loot: $5.24 from $6.99
Guise of the Wolf: $4.99 from $14.99
Jones on Fire: $2.24 from $2.99
Alan Wake Franchise: $19.99 from $39.99
King's Bounty: Warriors of the North: $12.49 from $24.99
Warlock: Master of the Arcane: $11.99 from $19.99
Blackguards: $29.99 from $39.99
Painkiller: Hell and Damnation: $9.99 from $19.99
Spacebase DF-9 Alpha: $19.99 from $24.99
Crea: $9.99 from $14.99
Ethan: Meteor Hunter: 4.95 from $9.90
Tropico 4: $14.99 from $29.99
Red Faction: Armageddon: $9.99 from $19.99
Red Faction Collection: $29.99 from $59.99
Retro Game Crunch: $12.74 from $14.99
SpellForce 2: Faith in Destiny Digital Deluxe: $9.99 from $19.99
Dungeon of Elements: $9.99 from $19.99
NOWHERE: $33.24 from $34.99
Please let me know if there are any typos or duplicates in this list, I tried to get it done as quick as I could. Please note that Humble doesn't distinguish between pre-existing discounts and spring-only discounts.
+1 for the work but it seems futile to list EVERYTHING, are there any standout deals?