One Day in Tokyo - Where Would You Go?

On my upcoming trip to Asia, Tokyo is one of the cities that I am most looking forward to visiting again.  My first trip to Japan was back in 2007 and was 14 days long.  We stayed in the famous Imperial Hotel, just south of the Imperial Palace, and saw pretty much all of the highlights of Japan.  We were entertained by the song and dance of geisha's, transcribed the sutra with monks at the Moss Temple, climbed Himejo Castle and were humbled by the remains at Hiroshima.  It was truly a spectacular trip!  Even the famous cherry blossoms were in bloom during our visit.  Brilliant shades of pink were visible out the windows as we road the bullet train through Japan at speeds of almost 200 mph.

My first (and honest) impression of Japan was that while it was incredibly, beautiful, clean and safe, it was the closest I will probably ever get to being dropped off on the moon!  I remember having some free time on that first trip and contemplated leaving the hotel on my own to explore some of Tokyo and to experience some of the local cuisine.  I've done a lot of traveling in my days and am usually pretty fearless about exploring new international cities.  I made it down the elevator, out of the hotel and about 50 feet away from the hotel and chickened out and ended up ordering room service instead. 

I did much better on my second trip to Tokyo, managing to get myself from the airport on to the correct train to Shinjuku Station, the busiest train station in the world.  From the station, I navigated my way to the hotel and even was brave enough to venture out to dinner...all by myself! 

I'll only have a day (at most) for sightseeing this time around and want to be sure to make it to a few spots I haven't visited on my previous trips like the Tokyo Tower, the Imperial Palace East Gardens and the famous Tsukiji fish markets (if I can wake up early enough).  I'd also like to find some unusual baby toys or clothes to take back to Olivia. 

 Where do you like to go when you visit Tokyo?  Who has the best ramen or sushi in Shinjuku?  What should I be sure to visit on my one day in the city?