Right at the instant AUDUSD has obtained over EURUSD as my current fave. major.
Reasons:
a) volatility: sensitive to big moves in gold
b) very positive fundamentals compare to europe, japan
c) maximum interest rate by far currently, fuel for carry trades
d) if you are based in america, aussie is great since you can get wind of this news usually between 7-10 PM EST during the night when I am home from work. Harder to warrant staying in a profitable trade when a major news event is expected at 3:00 AM or so when I am asleep.
At the conclusion of course, depends...