TurinI don't know if this is common knowledge or not, but USB headphones are much more reliable than normal headphones. Unless you're using it on stuff other than computers, then obviously go for the normal headphone jacks.
Really? USB has always been less reliable for me. You are forced to use the headphones driver which can often be buggy. In my experience you're much better off with standard 3.5mm headphones, especially if you have a decent soundcard.