The music and sexsound in games topics inspired this topic.
Personally i found it strange how many users mentioned headphones, so maybe this poll gives me some insight.
A bit part of the popularity of headphones is that they're much much cheaper than speakers when it comes to sound quality. You're going to have to spend well over a grand to get the equivalent sound quality of a $200 pair of headphones.
I use them for almost everything. For gaming and watching movies (the dialogue is hard for me to hear sometimes). I use over the ear headphones when i listen to music on my computer and earbuds when I go outside.