Trying to match someone via a picture if very difficult to do since the lighting in off and one person's monitor may be different than another in terms of how the colors look. To me you look to have a yellow undertone to your coloring but other than that I wouldn't attempt to tell you which MAC to try.
http://www.maccosmetics.com/product/158/13055/Products/Face/Foundation/Foundation-Finder/index.tmpl
http://www.maccosmetics.com/product/158/13055/Products/Face/Foundation/Foundation-Finder/index.tmpl