LOL Porsche doesn't make car covers anymore than they make battery chargers.It is definitely not even close to the best. I threw mine out after a year and had only used it three times.
Always provide as much info as possible versus just assuming that your notion of "best" is universal no matter what the topic. Outdoor covers a wide range of possible conditions (sun, rain, snow, wind, tree sap, impact, etc). Which specific conditions apply to your situation? Which are the bigger priorities? What's your budget? There are definitely prior threads on car covers that you can reference and even resources on car cover sites such as Covercraft's that explain the pros and cons of various fabric offerings for you to review.