Colorado, go to Boulder then over to Crested Butte.. although I guess that's a lot more MTBing based.
Thailand (but not quite the "sunny" season may still be to your liking)
US of A West Coast Pacific Highway including Death Valley.
South America..mmm would LOVE to go there!
Costa Rica, Cuba??
you hvaen't really given us a clue what you want to do, ie beach, city, activities, culture etc! I have LOADS of places I want to go and if you're spending £20,000 on a wedding then hell I say spend at least £3000 each on a honeymoon you'll probably remember it more!