I don't know about you, but I always hate to go into a new city and not know where I can buy the music I like. I mean, I know there must be some undergruond recor stores around, but because I'm not local, I can't find them. (Well I guess I could buy from the Internet, but what's the fun in that. )
So this is a thread of those off the beaten path kind of record stores that have no interest for the mainstream public.
My recommendation is:
Tokyo, Japan - Hard rock & Heavy metal Disc union in Ochanomizu
You can find Disc unions all around Tokyo, but most are specialized in other genres of music, like jazz or club music. There are also some general Disc unions with heavy metal corners, but if you are a heavy metal fanatic, the only place you want to go, is the Hard rock & Heavy metal Disc union right next to Ochanomizu railway station.
It is a small three storey record store dedicated to new and used heavy metal CDs and LPs. They have one floor for new CDs, one floor for used death/black/doom metal CDs, and one floor for used heavy metal CDs and LPs.
They have thousands of CDs and hundreds of LPs, and their collection is changing all the time, so it's hard to leave there without bag full of music. Sometimes, when you are lucky, and nobody hasn't beaten you to it, you can find some really rare stuff.
For the used CDs, the price ranges from 200 to 1500 Yen (1.5 to 10 Euro). Most prices fall between 400 and 800 Yen. The rare ones are much more expencive though.
As for new CDs, they usualy have both, the Japanese edition and the rest of the world edition. For example, last time I checked, they had one version of both, Rest In Sleaze and The Unattractive Revolution, and two different versions (Japanese and European editions?) of Generation Wild and The Savage Playground.
How to get there:
By far the easiest way to get there is by taking Sobu line train, which leaves platform 5, at JR Akihabara station. Ochanomizu station is the next station from Akihabara, and the shop is on the street next to/parallel to the station. It's the red dot on the map. The black dots are other Disc unions in the area, but they are specialized to progressive rock, classical music, etc.
I find this site awesome when I'm travelling. Some things can be a bit out of date, and places can be closed, but other than that, its really great.
But I can recommend some places here in Drammen/Oslo
Neseblod - second hand store in Oslo. They have tons of black metal, but also other things. Really small store, you need time to look trough stuff, but if you've got the time, you can find some real treasures. They've got cds, lps, cassettes and tshirts. And dvds and vhs. They have lots of rare stuff, especially in black metal. Its located at the old Helvete, where some guy from a black metal band had his store. (I'm not that much into black metal, so I cant remember his name) The place is kinda huge for black metal fans.
Strømsø plateforretning - second hand LP in Drammen. Not just rock/metal, but they have a lot of it. I've never gotten a dirty/bad vinyl from there, they only sell clean stuff. You can find some really cool stuff here. They have a box with rare stuff aswell.
Platevogna - second hand LP in Hokksund. Its basically a guy who has a "campingvogn" in his garden, where he sellls used vinyl. Again, not only rock/metal, but he has a lot of it. I guess its a bit hard to find this place as a tourist, but just ask, and I can tell you where to find it.
Hands down the best record store I've been to in the US is 2nd Avenue Records in Portland. Incredible selection of all types of metal in all formats, plus plenty of other genres that I never look at. The only downside is I can never escape without overspending. It's a huge store, but they don't even have room for all their stock and keep a lot of it in boxes stacked halfway to the ceiling.
Their web site does leave a bit to be desired, though.
"Though strange lay the waters from which they emerged, they glanced upon the world as their own; yet deep in their hearts they knew all the time that this was not really their home." -Watain, 'They Rode On,' 2013