Amsoil By far the best.
Any major brand synthetic oil.
Any name brand 10w30 would be fine. Don't mix synthetic and non-synthetic oils.
SAE 5w30 any major brand conventional or synthetic oil.
5W/30 synthetic oil is best, conventional petroleum base motor oil is acceptable but inferior, Brand does not matter with full synthetic, but beware, many are blends
Synthetic oil is synthetic oil. Any major brand will be of high quality.
Synthetic oil is synthetic oil. All brands are made from the same basic formula that has been around since World War 2. There is no real difference in any of the major brands. Buy the cheapest major brand. BTW, you will see no appreciable difference in mileage using synthetic versus conventional oil.
Mobil 1 Full Synthetic
Any major brand synthetic lube in the correct weight.
There are several companies that create synthetic diamonds or cultured diamonds. One such company that creates the best synthetic diamonds is New World Diamonds.
Ezip
The best motor oil for you car depends on the car. Many old cars can only handle regular motor oil.
20W50 is generally recommended by BMW for the boxer engines. They sell their own branded motor oil at the dealerships which is very expensive, but supposedly meets all of the requirements of the engine. You do not need to use synthetic oil.