Microsoft, Apple, Google.

An MS bug in an enterprise piece of software (so they get paid every year for it) is Skype for Business. Perhaps my org hasn't updated their installation, but if I drag a contact from the chat window (say you message me and aren't in my contacts yet) and then drag it to the contact list (in status view) it will reliably crash the program. If I drag it to groups view it'll place the contact in a group. My guess is that dragging it to status there is no "default" group and so there's some kind of null pointer exception occurring (it tries to add it but with group given as either junk or null).

I used to see more bugs in Outlook, but it seems somewhat better with the last update so I haven't noticed them. Though it was fun when I had negative 2 billion messages for a week or so (I certainly didn't have enough to cause overflow so I have no idea how it wrapped around like that).

Google's is an issue of usability of their webapps (IME), not strictly buggy but not sufficiently tested. Behind the proxy at work Maps is incredibly unreliable. It takes several reloads for it to actually start working "correctly", but don't change where you're looking too much (you can zoom in, but do not pan around). That's not the only unreliable one in this situation, but it is the most easily demonstrated.

Apple's Messages and Mail constantly tell me (they've been better the last few months, but it still happens) that I have unread messages, I'd search and search and never find them. Then I'd pull it up on a different device and finally see the unread message (which was both visible and marked as read on the original device).

Some of these may be shallow or seem petty, but it's an unpleasant experience that after so many years and with so much money should've been resolved for each of them. I'm willing to tolerate an indie game crashing on me. I'm not willing to tolerate an enterprise software solution (MS) crashing for a natural user behavior.

EDIT: I think resolved, but Apple's iOS calculator bugs were annoying for such a simple program. Not strictly a bug, but Windows' calculator, these days, is an unusable mess in many ways. It shouldn't require so many system resources to add some numbers together (the same could be said of many small utilities that were rewritten for, I think, Windows 10 or Windows 8).

Gmail showing me email meant for <first><last>@gmail.com instead of <first>.<last>@gmail.com. The fact that they ignored the . at all in the user names. The Youtube app on iOS when I first installed it and quickly uninstalled it years ago was an incredible annoyance. It wouldn't reliably show me the video I'd actually clicked on that caused the app to open.

Adobe is an almost perfect example of holding their market captive. I've run into a number of Adobe Acrobat issues over the years, though fewer recently (but I use it less often now). But especially Acrobat Reader on Mac OS X was awful, I actually once had to reinstall the OS to get it to stop fucking up PDF display even after uninstalling the software (I never found out what it had done to the system, and gave up). I needed it because I couldn't find anything else (at the time) that supported digital signatures in PDFs on the Mac (in the sense that it actually worked, I think Preview let me do it but what it made wasn't usable by the people receiving the file).

EDIT2: Another Google one, with Chrome on macOS in full screen. Hiding the location bar means you straight up can't get to it. You have to reenable it, versus a sane behavior like autohiding and moving the cursor to the top restoring it.