Only ones I really used seriously were Taki and Siegfred.
For Taki my weapon of choice is the Kris Naga. In SCII this thing not only did serious damage, but when charging it, it healed health. This weapon went on to be the best one for Taki in all the series from what I'm reading here. I still used it in SCIV.
Taki's reach is better than it appears. She uses 2 short swords but her attacks are one handed with extended arms, or she would attack while moving forward. Regardless of blocking or taking damage from Taki, she will be in close range. The Kris Naga was also pretty damn long for short swords.
Soul Calibur has a way of doing fake outs, and when we respond to fakeouts we literally see we've made a mistake and about to get a beating, and that's all we can process while having a chance to correct the error. In short the fakeouts made the player feel mentally stunned, like the brain is busy doing something else, and we can't react to the opponent slow charging a powerful combo opener.
Doing combos is easy, but advanced combos was too hard in SCIV.
When they said Taki is being removed from Soul Calibur 5, I was done with it even more. I predicted they'd bring her back and they did in SC6. I just looked at it and SC6 is so much faster, it makes me wonder if it's even playable as defending oneself in Soul Calibur was a bit of a rock paper scissor game between highs and lows, as were fakeouts.
Haven't played it in a very long time, and I don't know if I'll play again. Fighting games are only fun when we have people to play against.