It's easy to look out in the world and figure out what the most neglected body part in exercising: The Neck. It's not hard to find even a good bodybuilder with a poorly developed neck. That's also revealing to me because I think that the neck is the quickest way to determine whether or not someone is in good shape or not. When someone is overweight, even if they're the thin but overweight kind, you'll see the fat deposit in their neck. If someone has underdeveloped muscles, you'll see their neck seemingly sag under the weight of their head. That alone is a good enough reason to exercise your neck: It's the pillar that the brain rests upon!
The neck wasn't destined to be a weak body part. With it's thickness and short length combined with the multitude of muscles that support it (including the trapezuis, one of the biggest muscles in the back, is tied to the neck) makes it a potentially formidable body part. Still, it's a weak link on most bodies. What is especially pathetic about the situation is how EASY it is to get a strong neck.
Even 10 minutes of exercise twice a week will make your neck considerably stronger. If you did some self resistance exercises followed by some easy bridging work you will build up an enviable neck in very short order. You'd be hard-pressed to build up another body part to any degree in such a short period of time like you can build your neck. So keep it in mind when you're exercising.