I've been playing as Mitsurugi since Soul Calibur 1 (And Soul Blade, for that matter) so I'm not about to switch my main to anyone else, but when I play against people I usually just set it to random. :P I like playing as everyone. Except maybe Rock. It's kind of a shame. Rock was great in Soul Calibur I and then he disappeared for SC II and when he came back in III he was completely blah.
I played as Talim for the first time today. She's been denerfed, it seems. She's as fun as she was in SC II. :P And she's not going bald any more.