The one that works!
But seriously, every detailer and dealership is going to say they have the best, but the real question is which coating is Best for Your Car?
We will not include dealership levels of protection as a comparison as there is an abundance of information showing the how much a quality aftermarket is far better quality and also usually easier on the wallet.
In the aftermarket range, the ceramic coatings market is flooded with options. At the top of these options there are around 5 or so that stand quite high in their quality, durability and strong branding, which are established, sound businesses. You will find the top products all have a strong level of protection and hydrophobics, and typically last as they say they do, providing they are correctly maintained.
So choosing the best coating goes beyond what is in the bottle of liquid going on your car to having to review the quality of installers and ensuring they are trained professionals not just in applying but also in paint correction. Then you need to look at the company supplying the product to ensure they have correct warranty procedures in place, and the quality of service and likelihood that they will be around to answer your calls in the event of something happening.