I've been using CDJapan for many years, it's really the only place to get CDs and DVDs from the Japanese Artists I like. I've ordered so many Maaya Sakamoto CDs and concert DVDs/Blurays there (well, actually, all of them), that CDJapan have started adding random extra's like posters and stickers and whatnot

Also a great source for anime and game soundtracks. Way back the Final Fantasy soundtracks over here were a compilation on only 1 CD, whereas the Japanese releases were 4 CDs, and they cost the same ..