My wife is an art teacher. She appreciates all kinds of art. She explains art, like food. Foods come in all kinds of shapes, sizes, colors, textures, flavors, etc. And it's all good in its own way. People have food preferences, just like people have art preferences. You can't say whether a hamburger is better than a piece of apple pie. They're both great in their own way.
I had a hard time with Jackson Pollock and with Mark Rothko (the color fields painter) when I saw their stuff at first. But now I understand.
Photo realism is one of my favorite genres, because I love attention to detail. Wish I had the skill to re-create what the camera in my head sees, to reproducing it with my hands. I find that an amazing and rare talent.
Bob Dole mentioned Chuck Close. He's also one of my very favorite photo realist painters. One of his black and white works is in the St. Louis Art Gallery, and it's stunning in its realism. You can read about Chuck here:
http://en.wikipedia.org/wiki/Chuck_Close