Sgnuik, both Loft and Hands has it's head store in Shibuya (located pretty close to each other).
It depends on what you are looking for, but generally speaking the Shibuya stores tend to have more variety and are quite large (6 stories for Loft, 7 stories for Hands). At the same time, there are various things that are only available at other branches.
The following are the websites for Loft Shibuya and Hands Shibuya. For Hands, click the icons along the gray horizontal line near the top to see examples of their merchandise.