The first thread (https://www.gardenweb.com/discussions/2853539/lets-start-a-chain-reaction-game-get-some-activity-going-here#n=18037) was 18,037 comments and getting slow to load. So I've started a continuation thread here. Please let the first one lapse. For the record, the first thread was started by ravencajun Zone 8b TX on February 19, 2015 with "dog toy" and ended on June 18, 2019 with jemdandy's "corn stalk".
The second thread (https://www.gardenweb.com/discussions/5724532/let-s-start-a-chain-reaction-game-get-some-activity-going-part-2#n=5000) was 5,000 comments long. It started with Annie Deighnaugh's "stalk chopper" and ended on December 13, 2020 with hallngarden's "season joyful".