It's not quite fair to devote an entire category of complaints to products made by Microsoft, so I won't, but they are SO ANNOYING. Nor would it be correct to lump all of the products or features into a single post, since they are SO ANNOYING in such specific ways.
I have trouble referring to Microsoft Outlook as anything but Ouchlook. This moment's annoyance is a peculiar feature of the Ouchlook calendar:
Click on "day" to view a single day. It shows Monday. WTF? I don't want to see Monday, I want to see today.