I wear my Ariat Terrain H2Os EVERYWHERE. They are the most comfortable pair of shoes I own, outside my Adidas cross-trainers. When I ride, I just pull on a pair of half chaps and I'm ready to go.
The Terrain H2Os are water proof (I know this from experience! Lol), have a tread like a hiking boot and look pretty good, too.
I have them in a lighter color than this (think they may have stopped making the lighter color?): Endurance Boots Terrain H2O - Ariat
The trainer at our barn has a regular pair of Terrains that she wears all the time, as well. She does the same thing I do and just throws on a pair of half chaps when she's going to ride. She's jealous that mine are H2Os, though.
Here's the ones she has: Endurance Boots Terrain - Ariat
(For what it's worth, we both have the same color, which is called "Sunshine")