So ... 12 years. For a channel created to run a one-off D&D session with 3 people, I'm astonished it's lasted this long. (Two of the first players, for the record, never returned: D&D murder mystery is not to everyone's tastes.) The channel has seen many, many GMs and games throughout the years and had a lot of players, some of whom have been around, off and on, for over ten years. To say this is a surprise to all concerned underestimates it, to say the least :)
A few milestones that come to mind:
Sparkie, who came into existence as a joke NPC during the 'generic D&D games' that compromised the first months of Game1 and eventually turned into the Wasted World. When the time came for a dicebot, Sparkie got upgraded.
Wasted World. Spanning Three campaigns (for reasons of time travel, the second campaign and half the third technically never happened), it was the first real game1 setting and included everything from wizards with magic shops and pet Otyughs to gods among the PCs. A personal favourite highlight is the attempt of level 1 thugs to mug the PCS, en route back to the city they had acquired during a war. The players were convinced it couldn't be simple ruffians and the encounter lasted over an hour.
It's also the campaign that introduced Jeramias to D&D. He and a friend had browsed the books in a store, he ended up on game1 that night and his pc existed as an idea without stats for a whole campaign as he learned the game on the fly.
Callaran, a year-long D&D campaign that involved kender convincing evil clerics to be good and a vampiric halfling, among other highlights. Ended when the halfling killing other PCs for their attempted murder of him when he became a vampire and the bard being the only survivor.
LOLAD began life as a 'finish that character, a game will fun' incentive that ended up being game1's first foray into modern earth. (D&D 2e being used to run a modern game with vampire and werewolves. Insanity.) It had PC romances, AIs, werepanthers, necromancers, The Faline, dragons, werecows and lasted six months, spawning 2 sequels, another game set in the same world and the lolad 1.1 sequel that ended up being ran by Alcar and then re-envisioned by kentari in the game crossover idea*. It ran in D&D (2e and 3e), besm and a custom system at differing times. Confusing but fun :)
Hubris was the first truly insanely gm-intensive game that began the game1 superheroes games, spawned a sequel set 20 years later and ended due to GM burnout, which is still a regret. Probably the single most in-depth game I've ever done, in terms of the sheet amount of work put into both Hubris and Aftermath.
Shroomform. Just ... shroomform. (This sentiment can probably be applied to the Amber games as well.)
The Lands of Blood games. Aka: death gods without power, a succubi drunken master and a jedi knight, among other things. Stormtroopers and Sith crash-land on a D&D world with Cthulhu waiting in the wings. Probably even crazier than that makes it sound.
Several demented unknown armies campaigns have run, but trying to summarize them up would probably lead to this blog getting a mature warning label. Caltak's PC Hugh was in at least 2, maybe even 3, campaigns, making him one of the only pcs to do that trick.
Ios, a cliche-driven fantasy game in D&D that marked Game1's last 'serious' foray into D&D. To this day I am never quite certain how the hell the Lee/Lirk/Orgg love triangle really came about, but I think Theliar can be blamed.
kbesm, a modern besm game that got a sequel run by kentari and then by alcar*. Crazy-awesome fun all around. Generally any game that spawns sequels enters the pantheon of game1 awesomeness.
Unstrung Heroes deserves a special mention for having run since 2003. The first two sessions were six months apart, long enough that one player had forgotten he'd played in the game. It's ran off and on since them, often with a few sessions close together and a year (or more) gap between sessions.
* Alcar and Kentari ended up not wanting to run/continue sequels to lolad and kbesm, despite requests, so swapped settings. Dunno if it will ever be done again, but it was a lot of fun to run and the cross-over between both settings would have been epic had it ever come to fruition.