In no particular order:

• Basic Fantasy RPG
  
• Savage Worlds
  
• Dungeon World
  
• Mouse Guard Check under other purchase options. You can get it for about $19.40.
  
  You can't go wrong with any of them, but gun to my head, I'd say look into Mouse Guard or Dungeon World.
  
  

  Mouse Guard
  

  Mouse Guard...is just down right fun. While combat is certainly part of the game, it's got a heavy emphasis on problem solving in encounters over straight up murderhobo-ing your way through the game. It's my go to game for one shots. Perfect for when you need a break in the middle of a long campaign in another system, or if just not enough people show up for a session in your primary campaign. Not that you couldn't run a long campaign in Mouse Guard, that'd be rad.
  
  

  Dungeon World
  

  Dungeon World is also another great game for one shots, IMHO. Need to work on your improv? Play Dungeon World. It's a very narrative driven game that heavily encourages collaborative world building with your players. Additionally, if you discard all of the rules on classes and combat, the rest of the system is an amazing compliment to any other game system you want to run. It's GMing section is honestly the missing manual for D&D or any other system you want to run. And hell, Fronts are a great way to organize an adventure or long campaign.
  
  

  Edit: A few other options that came to mind
  

• Fate: Core System, or Fate Accelerated Everyone seems to either love or hate the system with no in-between. If you've played the Dresden Files RPG, you're familiar with the system. Fate Core was derived from the Dresden Files RPG.
  
• Bubble Gum Shoe This one is a lot of fun. Runs on the Gumeshoe system. Kind of an innocent system. Think Scooby-Doo mysteries, without the monsters. If you want something grittier, take a look at Trail of Cthulhu or Mutant City Blues.
  
• Monster of the Week This one is a guilty pleasure of mine. Game is exactly what you'd expect from the title. If you like episodic shows like Supernatural or Buffy, this is for you.
  
• Fiasco Haven't played this one myself yet, but it looks interesting. This is a game that doesn't require a GM and is entirely improv. Looks great. Requires six sided dice.

>Also interested in the idea of critical causing effects like scars and trips rather than a simple number modifier.

FATE might be something to look in to. It is genre-less and it doesn't deal with hitpoints etc so much as it deals with consequences of success and failure.

List of Influential RPG Titles

Dungeons and Dragons - By TSR and WotC

Dungeons and Dragons 1st Edition - TSR

• Core Rulebooks
  
• Adventures (Keep on the Boarderlands, The Tomb of Horrors, The Temple of Elemental Evil)
  
  Advanced Dungeons and Dragons 2nd Edition - TSR
  
  
• Core Books (PHB, DMG, MM)
  
• Unearthed Arcana
  
• Campaign Settings (Dragonlance, Ravenloft, Forgotten Realms, Dark Sun)
  
• Arms and Equipment Guide
  
  Dungeons and Dragons 3.0 - WotC
  
  
• Savage Species
  
• Deities and Demigods
  
• Stronghold Builder's Guidebook
  
  Dungeons and Dragons 3.5 - WotC
  
  
• Core Rulebooks (PHB, DMG, & MM)
  
• Expanded Core (PHB2, DMG2, MM2, 3, 4, 5)
  
• Psionics Handbook
  
• Unearthed Arcana
  
• Complete Series (Arcane, Adventurer, Warrior, Divine, Champion, Scoundrel, Mage, Psionics)
  
• Campaign Settings (Ebberon, Forgotten Realms)
  
• Adventures (Return to the Temple of Elemental Evil)
  
  Dungeons and Dragons 4e - WotC
  
  
• Core Rulebooks (PHB, PHB2, PHB3, DMG, DMG2, MM, MM2, MM3)
  
• Essentials (Heroes of Forgotten Kingdoms and Heroes of Fallen Lands, Rules Compendium)
  
• Settings (Forgotten Realms, Dark Sun)
  
• Adventures (Tomb of Horrors)
  
  Pathfinder - Paizo Publishing
  
  
• Core Rulebook
  
• Advanced Player's Guide
  
• Advanced Race Guide
  
• Ultimate Magic
  
• Ultimate Combat
  
• Ultimate Equipment
  
• Game Mastery Guide
  
• Ultimate Campaign
  
• Mythic Adventures
  
• NPC Codex
  
• Bestiaries 1-4
  
  Not Dungeons and Dragons
  
  World of Darkness - by White Wolf
  
  
• Vampire the Masquerade - Vampires are so mainstream now...
  
• Werewolf the Apocylypse - Where there are vampires there are werewolves.
  
• Mage the Ascention - and witches and wizards.
  
• Hunter the Reckoning - and someone to hunt them.
  
• Changeling the Dreaming
  
  "New" World of Darkness
  
  
• Core Book
  
• Expanded Core (Vampire, Mage, Werewolf)
  
  AEG
  
  
• Legend of the Five Rings 4th Edition Core Rulebook
  
• Legend of the Five Rings 1st Edition Core Rulebook
  
• 7th Sea
  
• Deadlands
  
  Other
  
  
• Shadowrun
  
• Savage Worlds
  
• Dungeon World
  
• FATE Core
  
• Call of Cthulhu
  
• RIFTS
  
• GURPS
  
• Paranoia - Super expensive on Amazon, not sure why.
  
• Elf Quest - Also a very popular graphic novel.
  
  Authors to Look for
  
  
• Gary Gygax - Role Playing Mastery and Master of the Game
  
• Monte Cook
  
• John Wick
  
• Dave Arneston
  
  RPG Related Non-Fiction
  
  
• Confessions of a Part Time Sorceress - Shelley Mazzinoble
  
• Of Dice and Men: The Story of Dungeons & Dragons and The People Who Play It
  
  RPG Fiction, also essential
  
  
• Dragonlance - Chronicles Triligy by Weise and Hickman - Set in a D&D campaign Setting
  
• Drizzit's Series - By R. A. Salvatore. Icewind Dale Trilogy and The Dark Elf Trilogy
  
• The Riftwar Saga by Raymond Feist - It's allegedly the story of the author's long running D&D game.
  
  Other Lists
  
  
• Good Reads Popular RPG titles.
  
• Wikipedia timeline of RPGs
  
  Honorable Mentions
  
  
• Star Wars - d6 Edition, d20 Edition, SAGA Edition, Star Wars RPG (Fantsy Flight)
  
• Star Trek - Various Incarnations
  
• Serenity the RPG
  
• D&D Comic Books
  
• Buffy the RPG
  
• Whatever the heck "Demon" is...
  
  *Please add suggestions below, I'll add to the list as I revisit this thread throughout the day. Adding Amazon links now.

What caught my interest is that the FATE Core System book is on sale too.

Anyone have any input on it? I've only seen was SomethingWhittyGaming's (The Sword Art Online Abridged guys) what-ended-up-a-one-shot run of a My Hero Academia game. Although when the second episode landed and they were using a different tabletop RPG system it generated one of my favorite lines: "Are you alright?" "No I'm not, she knocked the flying out of me!"

Check out FATE Core and FATE Accelerated. They are both "pay what you like (including free)". FATE Acceleratedin booklet form is only $5. FATE Core is less than $25 shipped.

http://www.faterpg.com