The only times that you'll really catch me using earphones nowadays is either if I'm not at home and have forgotten my headphones, or if I'm going on a trip, say to the shopping mall, where it wouldn't be the most logical of ideas to carry around a big set of headphones.
I mainly use headphones though, mainly because my pair has a built in microphone that is quite useful if you're chatting on TeamSpeak and trying to get something done in the kitchen at the same time. That, and the cups go fully around my ears, and have excellent noise cancellation. xP