In addition to what others have pointed out, I have found that a nice large front mud flap serves to dampen the vibration of the front fender. On my bike I notice a marked difference, without the mudflap I hear a rattle as the side of the fender hits the knobs on my tire every time I hit a bump, with the mudflap the fender never wavers regardless of the bump.

I think this is important as every model of fender I looked at has only two mounting points for the front fender (as opposed to three on the back) providing lateral stability. As a result it is very prone to a side to side vibration, particularly if the right sequence of bumps is hit at the right speed.