Yes, I agree with Zeromus. Masamune and Murasame are actually real words that have correct pronunciations so what some of you are saying is incorrect. However, pronounce it however you want, because no one really cares.

For words like Quistis and Tidus, the pronunciation can and will differ because there isn't a clear way to say these names. Well, Tidus is actually officially pronounced Tee-dus, but w/e.