I'm still holding out hope for lightsabers in the future but with our world's technological limitations and silly allocation of resources, the most beautiful deadly sword-type weapon we can create without lasers might be this mashup of a lightsaber and katana made by Man At Arms: Reforged.
It's mostly a katana with an intricately designed lightsaber handle but it sure is pretty to look at. And deadly. I wish they were able to change the colour of the steel or use a different metal or at least shine a light on the blade to make it look even cooler, though. [Sploid]