All airports in the US are GA friendly. Some are a bit hectic, like LAX, but you can still fly into them.
Normally if you take on fuel they waive any ramp fees - and may even lend you the crew car if you sweet talk the person behind the desk at the FBO
If they have "transient parking" you can park there for free though my advice would be to stop at an FBO though, take on fuel and then make use of their nice fresh cookies, coffee and mouthwash in the bog
