Logos are intentional, visual messages, not just pretty, whimsical pictures. Please appreciate the commonalities among these major brands: works great as single-color, text and other details kept to a minimum (including use of sans serif), graphic mark fits well within a square, rarely many colors, and color variations are clear to communicate or subtle to enhance.
Logo Design: Skylines from Logopond and Dribble. I like this design. It would be a great logo for a city, but of course the bridge & John Hancock tower would have to be changed because it's too SF. #NerdMentor