Shinjuku at night. Notice the temperature on the LISA, 36deg. Not at night of course, that is the forecast for the following day, but it was still hot when I took this picture.
Heat aside Shinjuku is an interesting place. When I think of places to go in Tokyo Shinjuku is low on the list. There are lots of places to eat, interesting night life (kabakura, host clubs & Golden Gai), decent shopping, but I would recommend many other cities to people before Shinjuku. For example Ginza for high life, Shibuya/Harajuku for youthful activities, Roppongi for fast living, etc. Don't get me wrong, Shinjuku is a fun place and maybe I just don't visit it enough, but that's because there are so many other amazing places in Tokyo to go. I guess it depends on what you are in to. What say you?