Lew from Unbox Therapy did an awesome comparison between in-ear headphones and over-ear headphones. He stated five reasons for each of them telling why either of the two is better than the other.
So if you are hunting for what headphones to buy and are confused about which one (in-ear or over-ear) to buy, these videos might help.
5 reasons why headphones (over-ear) are better than earphones (in-ear):
5 reasons why earphones are better than headphones: