I like Soul Edge more than anything else. It can take any form of weapon that it needs to (although it's usually as a great sword), fitting anyone's fighting style. Plus, the more you kill with it, the stronger it grows, and considering that it has been devouring souls since probably the beginning of time in countless wars and battles, that means it has become rather powerful by the point you would come across it. In fact, just having a fragment of Soul Edge on (or even in) you will increase your abilities and make you a formidable fighter. Sure, there are some drawbacks, like it's nemesis Soul Calibur being able to counter it when in the right hands, or the fact that it slowly devours the soul of its current user if they don't have a strong enough will, malfesting them into insanity, but the pros outweigh the cons for the most part!
Plus, I'm a ginger, so good luck eating at my "soul", Edgy.