The Shibuya branch of Yasubee (yah-soo-bay) is on Meiji-dori just south of Shibuya station, on the west side of the street. Down the middle of the street you can see the surface construction for the forthcoming new "line 13" of the Tokyo Metro. At 6:30 PM on a weeknight there was a line of about 10 people inside and outside the store. I had the shoyu tsukemen, which had a fairly sweet broth and very plain noodles. The sui goyza that I added to the order (4 for 300yen) were good but rather expensive for the size. Watch your head when you sit down and stand up as there is a coat rack and a luggage rack right behind the counter. All in all, while it was decent, there's nothing to specifically recommend this shop. There are somewhat better options in the area, for example Kookai or Sakurazaka.
Shop home page
Tabelog page (more pictures)
Diddlefinger Map (English labels)