Super rough estimates -
First Achievement - Dec 21, 2005 - The “New You” achievement in Tony Hawk's American Wasteland
First completion - Jan 04, 2006 - Peter Jackson's King Kong
Joins TA first GS milestone - 130,000 GS - Sep 18, 2010 - The first assignment achievement in DarkStar One: Broken Alliance
200,000 GS - Mar 11 2012 - Pull the Trigger achievement in Full House Poker (WP)
300,000 GS - Dec 14 2014 - Through the Night achievement in Game of Thrones: A Telltale Games Series
400,000 GS - Jan 02 2017 - Blind goes up! achievement in The Little Acre
500,000 GS - Jun 01 2019 - Brutal End achievement in Mortal Kombat 11
600,000 GS - Oct 20 2020 - Zoologist achievement in WWE 2K Battlegrounds
700,000 GS - Nov 07 2021 - Love achievement in Unpacking
800,000 GS - Dec 09 2022 - Quantity is Quality achievement in Marvel's Midnight Suns
900,000 GS - Oct 11 2023 - Emerald Gemerald achievement in Crash Bandicoot 4: It's About Time