You forgot about my favorite piece of bloated crap, Acrobat Reader. Why does it take the better part of a minute to start an application that views documents? Why is the installer 30 MB? Why is there a patch every other week for yet another vulnerability?
It started out okay, and was a great alternative to shuffling Postscript files around. But then they started adding features that few people really care about. And then scripting ruined the whole thing.
Unfortunately, since it's the "standard", hundreds of man-hours every year are wasted in IT departments everywhere patching this thing.