when it involve unknowns and therefore risks, it surely is a gamble!
my take is aud is the one to avoid; looking like falling further.
few reasons for this one to appr until their iron ore sales to china increase again.
further int rate cuts is possible.
usd strength will continue until we see the first rate hike in sep or dec. it is the expectation of this that is driving the $ bulls.
if by year end there is no hike, it may be seen as the fed is unconvinced it is time to hike; the $ bulls will retreat, i believe.
so, between now and dec, i expect the $ to stay strong.
sgd is probably the best overall bet. mas may let it float around a wider band but has enough muscle to keep it to an an optimal level for sg economy like it always does. i see this one depr marginally with usd but will gain on the rm for a long time.
happy buying or selling foreign currencies!

But cybermaster has a point. US$ cannot appreciate indefinitely. There must be a limit until their economy will be hurt.
But at the moment, I agree with you. US$ and S$ still the best bet