I have two copies of Wild Arms 1, because my original copy has a lot of scratches and doesn't work as well as I would like. So I replaced it with another copy but I still have both.

I have two copies of Soul Calibur II, which was completely by accident. I received the original back when it came out, but got my second copy due to picking up a copy of Unlimited Saga online and the disc was in the box instead. I offered to ship it back to them, but they told me to keep it.

On a more "technical" side of things. I own both the English and Japanese versions of Final Fantasy VI (SNES/Super Famicom) and Xenogears (PS1).