I disagree. The only ones I can stand are Sasami (who is like 8 years old and is more intelligent and mature than most of them, seemingly around for the pedophiles to lust after) and Kiyone (a smart, reasonable girl who is driven insane and has all of her career opportunities blown by her stupid bimbo partner). Ryoko--bitch. Aika--bitch. Mihoshi--walking blond joke. That girl that didn't exist--bland. Washu--don't care one way or the other.
Okay, I'll give you Sasami, but Kiyone never did much for me. The series already had one person playing the stressed out "straight man" role with Tenchi. I never really thought they needed someone similar. To each his own though. Ayeka, I believe is the most disliked character for most people who have seen the series. I love Ryoko's character because she shows more emotional and mental range than anyone else in the series, IMO.
Also, I forgot to mention it earlier but I think Inuyasha is a damn good series. I haven't ever seen Wolf's Rain though, and was wondering if it's any good.