There are lots of Blu-Rays "out there" that have subtitles that you need, but where it is hard to find the information that will help you find out 1) that they actually exist, and 2) which specific editions to buy.
Look for German, French, and Italian editions at the respective Amazon divisions. If your language isn't listed, try to find more info elsewhere, such as backside photos or reviews of the specific edition (example: google "Sag Niemals Nie" + blu-ray), and there is still a chance you will find that this specific edition actually has you language on it. (Try to take a look at "Deliverance" and "Excalibur" on dvdcompare.net, and try to take a closer look at the "German" edition of "Rosemary's Baby".
You will not always be in luck; the German edition of "The Ninth Gate" is strictly German, and the French edition of "pirates" is strictly French. (Both are Polanski movies, and the lack of true international editions is a great shame). But you *do* have a chance of finding some movies that you had more or less given up on.
Information about subs and other details (such as cut or uncut versions) can often be found at the user generated site dvdcompare.net.
Information on whether BDs from other regions are actually "region All" (which is often the case) can often be found at http://bluray.liesinc.net/