Best AWD system in the market!

For some regions - AWD cars are mandatory. In Canada (in most provinces) AWD cars much appreciated due to harsh winter. Almost every car manufacturer offers AWD cars. But the question is: which one is the best?

1. Audi's Quattro
2. MB's 4matic
3. Acura's SH-AWD
4. BMW's xDrive
5. Subaru's Symmetrical All Wheel Drive System
6. Mitsubishi's AWS
7. VW's 4motion
8. Lexus, Inifiniti, Mazada, Cadillac and Volvo offer AWD, i am not sure if they use the traditional AWD systems or unique like Quattro and Sh-AWD.

This is not in order. I just named them. If I forgot any manufacturer which makes special AWD system, please add.