Half-Life: Source - https://store.steampowered.com/app/280/HalfLife_Source/
Counter-Strike: Source - https://store.steampowered.com/app/240/CounterStrike_Source/
Half-Life 2 - https://store.steampowered.com/app/220/HalfLife_2/
Half-Life 2: Deathmatch - https://store.steampowered.com/app/320/HalfLife_2_Deathmatch/
Day of Defeat: Source - https://store.steampowered.com/app/300/Day_of_Defeat_Source/
Half-Life 2: Lost Coast - https://store.steampowered.com/app/340/HalfLife_2_Lost_Coast/
Half-Life Deathmatch: Source - https://store.steampowered.com/app/360/HalfLife_Deathmatch_Source/
Half-Life 2: Episode One - https://store.steampowered.com/app/380/HalfLife_2_Episode_One/
Half-Life 2: Episode Two - https://store.steampowered.com/app/420/HalfLife_2_Episode_Two/
Portal - https://store.steampowered.com/app/400/Portal/

Left 4 Dead - https://store.steampowered.com/app/500/Left_4_Dead/
Left 4 Dead 2 - https://store.steampowered.com/app/550/Left_4_Dead_2/
Alien Swarm - https://store.steampowered.com/app/630/Alien_Swarm/
Portal 2 - https://store.steampowered.com/app/620/Portal_2/
Dota 2 - https://store.steampowered.com/app/570/Dota_2/
Counter-Strike: Global Offensive - https://store.steampowered.com/app/730/CounterStrike_Global_Offensive/
Team Fortress 2 - https://store.steampowered.com/app/440/Team_Fortress_2/
Half-Life 2: Episode Three - этот эпизод должен был базироваться на source движке. К сожалению он так и не вышел.
Half-Life 2: Survivor - спец. версия для Японии. Выпускалась исключительно для игровых автоматов на основе ПК.

Vampire: The Masquerade — Bloodlines - https://store.steampowered.com/app/2600/Vampire_The_Masquerade__Bloodlines/
SiN Episodes: Emergence - https://store.steampowered.com/app/1300/SiN_Episodes_Emergence/
The Ship - https://store.steampowered.com/app/2400/The_Ship_Murder_Party/
Dark Messiah of Might and Magic - https://store.steampowered.com/app/2100/Dark_Messiah_of_Might__Magic/
Garry's Mod - https://store.steampowered.com/app/4000/Garrys_Mod/
Zeno Clash - https://store.steampowered.com/app/22200/Zeno_Clash/
Vindictus - https://store.steampowered.com/app/212160/Vindictus/
Dino D-Day - https://store.steampowered.com/app/70000/Dino_DDay/
E.Y.E.: Divine Cybermancy - https://store.steampowered.com/app/91700/EYE_Divine_Cybermancy/
Nuclear Dawn - https://store.steampowered.com/app/17710/Nuclear_Dawn/

Postal III - https://store.steampowered.com/app/10220/Postal_III/
Dear Esther - https://store.steampowered.com/app/203810/Dear_Esther/
Revelations 2012 - https://store.steampowered.com/app/201070/Revelations_2012/
Bloody Good Time - https://store.steampowered.com/app/2450/Bloody_Good_Time/
The Stanley Parable - https://store.steampowered.com/app/221910/The_Stanley_Parable/
Double Action: Boogaloo - https://store.steampowered.com/app/317360/Double_Action_Boogaloo/
Insurgency - https://store.steampowered.com/app/222880/Insurgency/
Contagion - https://store.steampowered.com/app/238430/Contagion/
CONSORTIUM - https://store.steampowered.com/app/264240/CONSORTIUM/
Blade Symphony - https://store.steampowered.com/app/225600/Blade_Symphony/

Black Mesa - https://store.steampowered.com/app/362890/Black_Mesa/
The Beginner’s Guide - https://store.steampowered.com/app/303210/The_Beginners_Guide/
Codename CURE - https://store.steampowered.com/app/355180/Codename_CURE/
INFRA - https://store.steampowered.com/app/251110/INFRA/
Transmissions: Element 120 - https://store.steampowered.com/app/365300/Transmissions_Element_120/
Day of Infamy - https://store.steampowered.com/app/447820/Day_of_Infamy/
Fistful of Frags - https://store.steampowered.com/app/265630/Fistful_of_Frags/
No More Room in Hell - https://store.steampowered.com/app/224260/No_More_Room_in_Hell/
G string - https://store.steampowered.com/app/1224600/G_String/
Bear Party Adventure - https://store.steampowered.com/app/1274450/Bear_Party_Adventure/
Apex Legends - https://store.steampowered.com/app/1172470/Apex_Legends/
Titanfall - Действительно задействует Source движок. Не издаётся в Steam.
Titanfall 2 - https://store.steampowered.com/app/1237970/Titanfall_2/
Counter-Strike Online 2 - Бесплатная версия игры для Японского рынка при поддержке Valve.
Hybrid - Об этой игре вообще ничего не известно. Она выходила только на Xbox 360.
Tactical Intervention - По неизвестным мне причинам игра навеки пропала из Steam.
Half-Life 2: Episode Four - Официально отменён. Разработкой должна была заниматься Arkane Studios.
The Crossing - Не издаётся в Steam.
Kuma\War - не издаётся в steam, либо каких-то других магазинах.
The DinoHunters - не издаётся в steam, либо каких-то других магазинах.
Dogfights: The Game - не издаётся в steam, либо каких-то других магазинах.
Dark Messiah of Might and Magic: Elements - эта версия игры не издаётся в steam, либо каких-то других магазинах.

Age of Chivalry
Alien Swarm
D.I.P.R.I.P. Warm Up
Dystopia
Half-Life 2 : Lost Coast
Pirates, Vikings and Knights 2
Team Fortress 2
Zombie Panic! Source
Blade Symphony
Counter-Strike:Source
Day of Defeat:Source
Dino D-Day
Half-Life 2
Half-Life 2:Episode One
Half-Life 2:Episode Two
Half-Life 2:Deathmatch
Half-Life 2:Deathmatch Source
Half-Life:Source
Insurgency
Left 4 Dead
Left 4 Dead 2
Nuclear Down
Portal
Portal 2
Zeno Clash
g-string

Спасибо за внимание! Надеюсь, что это руководство поможет тебе.