I really enjoyed it when I visited about four years ago. Looking through the brochure from back then, 4 out of 8 restaurants have been changed. I can still recall Fukuchan had pork bone odor, but the soup was so heavenly. Order the small bowl if you want to try more than one restaurants.

My favorite blog on ramen: http://ramen.livedoor.biz
It is all in Japanese but the pictures are worth a thousand word. This blog started in 2004 as a challenge to eat 100 bowls of ramen in a month and snowballed from there. Now he has been to almost 700 restaurants and consumed over 1100 bowls.

Each has their own pluses and minuses. You can see slightly better from Tokyo Tower due to the lack of nearby skyscrapers and dimmed lighting at night. They do charge 820 yen admission fee...