The Durgin bridge in Sandwich, NH.
A do-over of one of my first "keepers". The original was shot five years ago with my first camera - a 2MP Olympus point & shoot. Here's the 2002 version - http://www.knepley.net/nh_bridge.html - they've changed the mailbox. The do-over has improved image quality (especially sharpness) due to better lens and technique (including a tripod which I use 100% of the time now, but didn't own in 2002), and improved composition due to five years experience (and over 100K shutter releases).
The biggest composition improvement came from recognizing the importance of *separation* - in this case separating (avoiding overlap) the mailbox and the bridge. The other composition elements - foreground visual interest (mailbox) and leading (diagonal)lines (fence/road) seem to be wired into my brain as I did those sorts of things right from the start without having them "preached" to me. And, filling the frame with no wasted space is a no-brainer (crop in camera, not PS).