A bowl of ramen consists of four basic elements: the broth, the tare, the noodles, and the toppings. The broth is generally a mix of pork, chicken, seafood, and vegetables, with each shop crafting their own blend. Most mix various parts of pig and fowl, some add more complex elements, and some never reveal their secrets.
Before this article I didn't even know so many kinds of ramen existed. For me ramen has always been just ramen. Next time I am in Japan I will need to find places that serve those less common kinds of ramen and try them.
Hakata Ramen is the most popular out of this lot. There is one good Kumamoto Ramen shop about half a kilometre from Akihabarals central street. Chrome Ramen is a bit less common but again there is a shop in Okachimachi, one station on Yamanote line on Akihabara.