Within the 23 wards, Ginza is not really known for ramen overall, but it does have a few good shops to write about. Kinmaru is a tonkotsu ramen shop a bit off the beaten path in Ginza, a few blocks away from Chuo-dori. They opened in May of 2007 and their tonkotsu ramen has an excellent tonkotsu taste, some of the best I have ever had. Not too crowded at 1 PM on a cold Saturday afternoon. Ramen Jiro starts with this type of taste, then they add the shoyu to it to make a shoyu tonkotsu blend. If you go to this shop, or a good specialty tonkotsu ramen shop, you will be able to taste the base "Jiro" flavor if you close your eyes and concentrate. In Kinmaru's tonkotsu broth, there were occasional small chunks of suspended fat (abura) that really contribute to the taste. I also taste a bit less salt in this broth than Ippudo's. A chain ramen shop like Ippudo probably filters out the suspended fat chunks due to consistency concerns, e.g. they want every Ippudo to taste the same, however for an individual shop they can really add to the shop's flavor and make a name for it. Kinmaru offers 5 levels of hardness for the noodles (including two "extremely hard" levels) and you can order kaedama (an extra helping of noodles) for 150 yen. The noodles at Kinmaru are a shade thicker than Ippudo's standard style thin tonkotsu Hakata noodles, which are used by many other shops too. The scallions (onions) and menma are also excellent. You can get tsukemen but that dish comes with the regular pork by default. Both kaku-ni (boiled pork belly) and regular chashu are available, and as like at Ippudo, Kinmaru has fresh goma grinders and fresh niniku for crushing into your bowl, be careful with the fresh garlic as that stuff can squirt all over the place.
Livedoor Gourmet page
Diddlefinger Map (English labels)