rpg

First I'll double up on this one:

Amber Diceless Roleplay

Pair it with Theatrix so you can see two completely different approaches to diceless, non-stochastic games. Amber and Theatrix make a fascinating "compare and contrast" study.

To your list I'm going to add (or at points replace with):

• Chivalry & Sorcery (1st edition)

The first game designed from the ground up as a social simulation where your character's place in society is far more important than grubbing through dungeons, killing things, and looting their bodies. (Indeed for some characters that would negatively impact their experience and growth!) I might put it alongside Traveller to show the difference between a game having a setting and a game being the setting. Also the grandfather of later "mega-mechanics" game systems.

• Bunnies & Burrows

To my knowledge the first attempt at making a game (and a pretty CRUNCHY game at that!) that is 100% based on non-human protagonists.

• Runequest (1st or 2nd edition)

First non-class-and-level game. Second game that came with a detailed, very non-European fantasy setting. Maybe put it alongside 1974 D&D to show how early people started breaking off from the D&D style.

• Maelstrom Storytelling

I'd actually replace Apocalypse World with this because it is the very first game, to my knowledge, that broke completely free of even the vestigial wargames roots of RPGs, complete with traditional story structuring being part of the game mechanisms, no fixed attributes (and no numerical ones), scene-level resolution (you roll once for an entire scene, not turn by turn). It's innovative enough that it's of interest. It's good enough that it's worth studying. And it has enough mis-steps and flaws that it's worth discussing. Pretty much any "storygame" owes a debt to this game.