B&W, definitely. the lightness of the roof, the straightness of the shot (color one seems to have a right to left tilt for some reason), and the duck make the bw one stand out. also, the bw one causes my eyes to want to search around and find details, which is good for this image. not because there is no subject, but because it seems more interesting. The reason bw works in this image (to me at least) is because it's something that you would obviously expect to see in color, and a black and white images helps you to look closer at an image rather than as a whole. for me, in color images i see color, and that's what my mind sees, which can be reaaally good of course, but only if the colors truly make the image more intriguing. In this shot, the colors are just what you would expect and nothing too extremely fascinating (not bad, just not gorgeous). When i see black and white, i see details, and that black and white shot has many interesting details. The only thing i like better about the color shot really is the framing. The wooden thing on the right side of the image (next to the duck) in the BW one is a little distracting to me. all in all, i just wrote waaaay too much. and you probably didnt want to hear all that. oops.
great shots, i do prefer the BW one though (why couldnt i have just said that instead??)!