And here we are:
1) Dungeons & Dragons until your character surpasses the highest level in the book.
2) Burning Wheel for 2-5 years, until you see all of the moving parts turn and move.
3) The Shadow of Yesterday until a character Transcends, then fiddle with the Pools and make your own setting and repeat.
4) Dogs in the Vineyard for a dozen towns. When you start play, photocopy your post-Accomplishment character. After a dozen towns, see what that kind of life does to a kid in this game.
5) HERO by making up a character.
6) My Life with Master until the endgame.
7) Mountain Witch with a full table of six players.
8) Sorcerer with a published setting until a character reaches 0 Humanity, then make up your own setting and play it again.
9) Shock: Social Science Fiction until you have a metric butt-load of minutae from the same world.
10) Houses of the Blooded until a character dies of old age.
11) Breaking the Ice until everyone is feeling flirty.
12) A Thousand and One Nights until someone’s character is beheaded by the Sultan and you have eaten good food or smelled a delicious smell.
13) Lacuna until you have answered all of the questions raised for yourselves.
14) Dust Devils until someone’s character dies tragically because of their own shortcomings.
15) Burning Empires until you have played through all of the phases three times with three different worlds.
16) InSpectres until, I dunno…
17) Now make up your own damned game.
18) PTA for two full seasons.
That oughta do it.
But if you want to add some more:
19) NPC in a boffer LARP until some sleep deprived player hits you on the head with a piece of foam and PC in a boffer LARP until your character dies.
20) Host a Parlor LARP.
I couldn’t do just 12 and I missed Don’t Rest Your Head, Trollbabe and a slew of others…ELFS until you have had your fill of poop jokes (which is a rough one for me…never) and so on.
GLARING OMISSIONS: The earliest iteration of D&D, Moldvay D&D, Polaris, Universalis, The Pool, Capes, Carry, Steal Away Jordan, Grey Ranks, Spione, 1st edition of Vampire: The Masquerade, Amber, Prince Valiant, Over the Edge, Agon
What does your list look like?