For those who choose not to get married in a church, the options are pretty mundane. You could opt for a courthouse, hotel, park, beach, hockey arena, etc.
In Japan, an architect, Klein Dytham, has designed the Leaf Chapel for ceremonies. It overlooks a pool for a serene setting, has special lighting effects to add drama, and it just looks cool. No doubt acoustics are excellent too. Made of two movable parts, the leaf can be closed, then opened when the couple is married to show them the new world they face.