We've chosen April because it is our Anniversary month and because we find the weather just right for us.
Plus as long as you go for the end of April or beginning of May (depending on when Easter is) you miss a lot of the holiday days and it isn't so busy, or that's what we've found in the past.
Plus as the rhyme says:
Marry in April when you can, Joy for Maiden and for Man

Marry in the month of May, and you'll surely rue the day