Urban decay photos by far are some of my favorites, along with certain types of photojournalism and landscapes. Abstract stuff just doesn't do it for me.
I'm from Milwaukee, and let me tell you there is a ton of urban decay here, which is probably why I like it a lot. Once all of the industries left for China, they literally just abandoned their buildings. They built a bridge across the Menomonee river valley just so you don't have to drive through it, which is sad in a sense.
I'll have to get my photo site uploaded with some of my new shots.