#1 - MS Money - There are no personal finance apps of the caliber of MS Money (or for that matter Intuit Mint, which Intuit pulled in 2015) on the MS Store. MS prides themselves on being the platform of productive people. But I have to ask, what could possibly be more productive than personal and small business finance?
They could even create a cloud version and bundle it with Office Online. They could create a Win32 version and bundle it with Office 365. Having MS Money would be the product that would put me over the top and get me to actually pony up the monthly/yearly subscription.
#2 - Groove - A truly great app, and no good reason for this senseless killing other than Nadella hubris... chasing the AI dream.
#3 - Movie Maker
#4 - Windows 10 mobile - Should MS release Andromeda this year all will be forgiven.
#5 - Skype - I know technically that still exists, but there's a lot of anger about it. It duplicates contacts 1/2 the time. On some of them I can SMS, on others I cannot. And it's different versions of the SAME contact. It's confusing. I can "send" SMS messages, but I can't receive them? And it doesn't do audio messages like Voxer. It's angered so many people I fear its days are numbered.