For an interesting visual impact to be created, vintage window styles can come in very handy. Not only do they make for an interesting look from the outside, they offer a different indoor perspective as well:
The Quatrefoil window:
This sort of window is in the shape of a four leafed clover, and is evocative of a Gothic ambience. These can be plain or fitted with colored or stained glass to offer interesting shades of light or color.
The Fanlight Window:
Traditionally this is a window shaped like a fan as the name suggests, and usually sits atop another window or even a door. It can be not just an interesting design element, but it can be a source of natural light into the room.
The Bay Window:
This one is evocative of days gone past when there was time to sit by the window on the widow seat and read or just watch the trees growing. A bay window offers light and air to the room and the semicircular shape offers a view of the outdoors the way other window types cannot.
The Dormer Window:
The sloping roof of a house fitted with a dormer window with its own little roof is an eccentricity of days gone past, that can add charm to any modern home.