I have a bit of a "thing" for European DS game cases.
Oh, get your minds out of the gutter. I don't mean that I, uh, do things with them; I mean that I have an odd attraction to them.
It all started when I bought a copy of Freshly-Pickled Tingle's Rosy Rupeeland from the UK. For some unknown reason, that game's clear, thicker-than-the-ones-we-get-in-North-America case (see it in this photo) appealed to me so much that I wanted a few more.
I got my wish a few months later when I picked up a copy of the Euro version of Professor Layton and the Curious Village. (Here's a photo of it, in case you're, er, curious.)
There was, it seems, no turning back after that, as I quickly added Euro copies of Professor Layton and Pandora's Box, Professor Layton and the Lost Future, Last Window (the sequel to Hotel Dusk: Room 215) and Jam with the Band to my collection of DS games. (Photos of the aforementioned games can be seen here, here, here and here, respectively.)
Sadly--for my bank account, especially--I'm not through purchasing such games. I plan on picking up a copy of the Euro release of Inazuma Eleven at some point this year, for instance, and I also hope to buy a copy of Professor Layton and the Spectre's Call (the fourth in the series--it was called Professor Layton and the Last Specter in the States).
After that, though, I probably put a cork in this particular obsession--or at least that's what I'm hoping to do.
See also: Other reasons I could be considered an 'eccentric' (aka bat-sh*t crazy) gamer