http://min.us/mcQeomk

I saw this thing built in the middle of nowhere, and I realized how perfect it is as both a defensive wall and as an offensive sniping perch. Here are a few bullet points to support my case.

   ◘ It is 4 blocks tall, so the enemy isn't going to be able to shoot over it into your base. They also will have a harder time lobbing nades over the top of it.

   ◘ The ledge is high enough to give you a slight height advantage over advancing forces, and since the ledge is is only half way up the wall, you'll have room to crouch down and avoid enemy fire between your shots.

   ◘ The base is 2 blocks thick, so it will take twice as long for the enemy (or a griefer) to knock down the wall. However, it isn't thick enough for the enemy to be able to hide inside of it.

   ◘ Since the ledge is two blocks high, you won't accidentally walk up it while hiding behind the wall. It also allows you to safely drop off the ledge and move to a different position on the wall without being seen.

   ◘ Since it's so tall, the enemy will not be able to scale it as easily.

   ◘ If you put it on the coastline, the enemy will need to break a lot of blocks in order to climb up. On top of that, if your wall goes all the way around, you will be able to see where the enemy broke inside and hopefully follow them back out and kill them before they can get the intel back to his base.

If you aren't already building your walls like this, you should start. They take a little longer to build are are sort of resource intensive, but the end result is undeniably good. It can also be incorporated into other types of structures, such as pill boxes and fortifications.