"Best" is debatable; do you have a brand of oil, that you prefer? Once, you figure out what brand you like; you can look up on their website and find which oil meets the Volkswagen specification, that your car requires. Pretty much; every oil brand/company, makes a oil that meets the spec Volkswagen has, so it is just a matter of picking one. Lately, it seems; many people like Amsoil, the German brand LIQUI MOLY and Castrol.
It's recommend and/or preferred to use oil that meets a manufacturers spec/approval.
BUT this being said there is actually a lot of give and take here.
While the vehicle is under the Powertrain Warranty it would be foolish not to run a spec/approved oil. After that you can pretty much do what you want as long as you do things smart.
Some people run non synthetic oil in these turbo engines, I WOULD NOT recommend this.
I would say any name brand synthetic oil is wise to use, but be careful about the oil change interval if you are not running the VW spec/approved oil. You may want to change the oil and filter more frequently if you are not using a VW spec/approved oil.
BUT even if you are using a VW spec/approved synthetic oil, this does not mean you should mindlessly run the oil changes to the MAX mileage. There are MANY factors that contribute to premature oil contamination in as few as 1500-2000 miles. If the engine is not running at the proper temperature which happens very frequently with German cars, they often run too cold due to soft failing thermostats this will kill the oil very quickly. Same is true if you drive short distances in the Winter and do not allow the engine to operate at the full engine temperature for 15-30+ minutes.
You need to frequently check the oil level and pay VERY careful attention to the oil color on the dipstick. If the oil is ever BLACK, change is immediately regardless of how many miles you have driving on the oil. Engine oil that is black is heavily contaminated and will quickly cause problems for the engine.
I start out the Fall season with fresh oil in all of my vehicles and change the oil in the Spring unless the oil is turning dark too quickly. Water and fuel in the crankcase needs to be "cooked" off and Winter driving is very hard to the crankcase on a well maintained car and can really be devastating to poorly maintained car, a engine that runs too cool and an engine that is not fully warmed up and driving at full operating temperature for 30+ minutes at least once a week.