I reckon DD/MM/YYYY, mainly because I'm used to it.

For business and such, surely it must be easier to ignore the front part than the middle? I mean, If you need to know the month and year, you look at the last part of DD/MM/YYYY, but if it's MM/DD/YYYY then you have to look at the first and last, if the middle isn't important.

Anyway, for things like a forum, the Date is most important, no?