Menya Inaba, in just a minute or two from Showa Dori, going north on the opposide side from Yodobashi Akiba in Akihabara. They serve an excellent tonkotsu gyoukai, with generous portions of broth and noodles. The broth is very full and firm and rich, with extra powdered pork floating on top of a strip of nori. The noodles - the futsu mori starts at 270 grams - see the Ikemen link below for better pictures of the ticket machine and the menus that indicate the different sizes for noodles for ramen vs. tsukemen. They state that their noodle amounts are bigger than other shops and I can believe it. They can also serve the noodles warm, or provide a smaller portion if you request it. Menmas are also served with the dish. I believe this is a good Tetsu and Rokurinsha competitor in this genre, within 10 minutess walk north from Yodobashi akiba and across Showa dori. It's a fairly roomy shop. The pork was excellent, a somewhat fatty dark and light cut, each piece a decent size. 2 more slices is 300 yen. The shop proprietor and the person I assume was his wife were joking around. When he had a free minute, he told me that the pork soup cooks for about 10 hours each day. The powdered pig and fried garlic chips were excellent. Use the "niku mashi" (肉 増し) button on the machine to order more meat.
Raumen Nengo page
Diddlefinger Map (English labels)