QuickTime, how I love those frequent updates that require me to reboot.
(For long enough, only my Mac required a reboot on QuickTime updates - the PC managed to do it without a reboot. That has now been fixed and the PC has to be rebooted as well.)
QuickTime, how I love that you can't remember the volume the last time I played something and so just assume I want the volume to be at max 100%.
QuickTime, how I love your embrace for closed proprietary codecs.
QuickTime, how I love how you take away the focus from having a flash player in the iPod.
QuickTime, how I love how you register yourself as the default app for a bunch of video file types and then play only the audio for them.