Sunset is hard to beat, photographically speaking. The colors can be intense, the clouds sometimes get a bit radical, and if you are perched up high looking over a great town - like say, San Francisco - it just all comes together and forms a beautiful scene.
I was on the rooftop of my friends' place in North Beach. The sunset started out sorta boring actually, but that just goes to show you that you should never pack it in early because things can change very rapidly!
Technicals: 7 exposure HDR, f/11, 14-24 wide angle lens (at 24mm)
Software: Photomatix, Color Efex Pro, Aperture