CD shops on Internet

• CDworld Not huge but some decent prices. Worth a look.
• NoteWorthy by http (follow the links) or by telnet.
• Global Electronic Music Marketplace Slow and seemingly unstable.
• CDnow! by http or by telnet. Generally pretty good but perhaps a touch slow.
• CD Connection
• CD Europe Large selection of imports (depending of course on where you live). Some hard to get stuff. A tad expensive.

CD shops in Tokyo for western music

• HMV - Stores in Ikebukuro, Shinjuku, Shibuya and Ginza. They claim that the Shijuku store (My City) is the largest CD store in the world. Pretty big but doubtful. Ikebukuro (Metropolitan Plaza) has a huge classical section.
• Virgin Megastore (Shinjuku 3-chome). Pretty good. The demo CD players are always though.
• Tower - Stores in Shinjuku (2?) and Shibuya at least. Shinjuku (Lumine 1) is pretty good. lots of listening stations.
• Wave - Roppongi and others. Wave has lots of variety and some pretty hard to get stuff. The problem is that they don't organize it in any way that actually helps you find what it is you are looking for. They just take the CDs out of they shipping box and stick 'em on the shelves (or so it seems). I have never found anything I was actually looking for. A touch pricey.