X360 owner here! My favourite character to use is Mitsurugi.
The reasons are pretty simple - he's a samurai, he's got a badass attitude. And not to mention I love katanas. That was what sucked me in as I started my SOULCALIBUR career couple of years back.
His playstyle also suits me to a T - he is a very flexible character, being able to use spacing and zoning to good extent, and with his strong Mids (e.g. 33_66_99B, 4KB) (even more dangerous against a wall) and lows (e.g. new 2K BE B in V), which enables you to rush and unleash his mixup potential on the opponent.
In addition, his couple of good poking moves (e.g. 6B series) - which and prove useful against, say, impatient players - safe when guarded, advantage upon hit.
Also, his stances add more variety to how he fights. Though lately this has changed with him retaining only MST, he is still considered very strong in other aspects of the gae.
Being a straightforward character to use and play (yeah, I dont tend to think too much) - excellent pokes, great mixup game - is what I love about the sole SC samurai in the series.
P.S. KAAAAATS!