Fucking amazing!
It really does feel great to quit. After a short while you'll notice the following:
Other minor medical issues may get better from quitting, for example: my chest and back acne no longer exist, random chest pains gone, fingers aren't yellow anymore, I don't get horrible chest colds not nearly as often as I did while I smoked.
Those are just a few examples off the top of my head. As you can see there's plenty of reasons why it feels absolutely fucking amazing to finally give up that god damn cigarette habit forever.