Clip-on bars, triple clamps and steering dampers are actually quite simple parts, and while stock bikes come from the factory set up pretty well there's certainly room for improvement. Aftermarket clip-ons offer various adjustments to get just the right fit, and they can also provide better leverage than the short, non-adjustable stock units.
Another part that comes on many modern bikes is a steering stabilizer, but stock stabilizers aren't adjustable to suit the various riding conditions we encounter. Higher quality stabilizers are easy to install and provide the much needed confidence and performance that we all desire.
Holding the entire front end in place is the top triple clamp, and while for some it might simply be an easy and effective way to dress up your ride's appearance, for other set ups it's a necessity; some of the most commonly lowered bikes such as the ZX-14 and Hayabusa require an aftermarket top clamp in order to lower the front end. So there is some function to the form after all.
Whichever component(s) you choose to upgrade, you can be sure it will not only make your bike more unique but also more enjoyable to ride.