Quicktime bugs the heck out of me - not because it's Apple, but because it pops up a nag screen every time it runs, takes over file associations, and doesn't play well with others.
RealPlayer is even worse - it installs services, schedules popups, etc.
"QuickTime Alternative" (http://download.betanews.com/download/1049831315/quicktimealt122.exe / http://www.free-codecs.com/download/QuickTime_Alternative.htm) replaces QuickTime
”RealPlayer Alternative” (http://fileforum.betanews.com/detail.php3?fid=1054136293 / http://www.free-codecs.com/download/Real_Alternative.htm) replaces RealPlayer
Then you will be happy.