I use two boots to ride and work around horses.
One is a pair of Ariats. They are plain black, but look more like a pair of English-style paddock boots. However they are SO comfortable. I could wear them all day... and by the looks of them you could probably tell that I do. Time for a new pair!
A more Western style boot that I wear are my Tony Lama 3R series (which stands for "ranching, riding, roping" I believe). The are have a gorgeous design and are very comfortable and flexible. Didn't take much to break them in. The sizes seem to run small however; I usually wear a 8 in womens... my Tony Lamas are a size 6 1/2 womens.