First I played on an emulator, because there was no way I was going to spend the money to import from Japan.
Now that I have the games, I'm stuck playing on an old DS. My DS Lite broke (can't read games anymore because a piece inside is broken), and a fat DS was my only spare. The direction pad is wonky, so I wind up walking into walls all the time. But hey, it works.
I will be upgrading to a 3DS as soon as it comes out. So in two-ish weeks, I'll be playing the games on that beast.