https://killedbygoogle.com/
Killed by Google is the open source list of dead Google products, services, and devices. It serves as a tribute and memorial of beloved services and products killed by Google.
You can pick anything, even ones killed by Google!
I think I just started using reddit more to consume news, most of the feeds I read were turning into complete crap by the time it closed down (looking at you gawker websites)
Top 2:
Inbox was the best email client I had ever used, they killed it saying features from inbox would come to gmail... don't think they ever got added, either that or what they did add changed so much they are no longer like what they were on inbox for me to notice.