If your problem with the standard earbuds is comfort, you may not need to go all the way to over-ear headphones for relief. I use some inexpensive JVC earbuds with marshmallow soft earpieces
that produce decent sound and are very comfortable even after long periods. I even sleep with mine in sometimes, which is something I never could have done with Apple's standard issue buds. They do a pretty good job of blocking out external sound too. Best of all, they're only $10-15 or so (even cheaper for some colors). Search for "JVC Marshmallow" on amazon.com or click on the picture below for a black pair that's selling for $10.70.
If you have other reasons for wanting over-ear headphones (super audiophile, ears get cold, etc.), sorry for wasting your time.