I was asked this question the other day and then given a dirty look because the date didn't have any special meaning. I felt a little offended by the look.
We choose our date because I want an outdoor wedding, and early June here in KY it's not too hot, bugs haven't made their way out yet. And there is still enough daylight to enjoy the reception.
The only other date we have that has special meaning in Jan 20. And I do not like cold weather, and don't want to be miserable on my wedding date.