Originally Posted by Vendot

Sure JFK.... talking to the right man.

The answer for China is mainly Dot Com and Dot CN:

2L, 3L, 4L (without the letters A, E, I, O, U, V)

2N, 3N, 4N, 5N (without the numbers 4, 0, 1)

Certain combinations work in certain cases.
With numbers 7, 8 and 9 are favored too.

Also the more premium are ones with repeaters:
For example: 77538.com or MMTG.com