I dunno why but personally...I've always been a fan of Android 17 and 18 from DBZ. 17 has a voice that is pure awesome sauce (and it was a huge bonus to me when I found out he did the voice for Hiei in Yu Yu Hakusho when I watched that), and 18 has the appearance.
Also Yoko Kurama (And Suichi Minamino), Jushiro Ukitake, Soi Fong, Grimmjow Jaggerjaques, Coyote Starrk, Willow Rosenberg (especially evil willow, vampire willow, and if we include the comics, evil vampire willow), Darleen Connor, Link, Balthier, Remmy Le-beau, Zidane Tribal, Kuja, Delirium from Sandman, Harley Quinn, Katara, Korra, Naraku's Heart, and so many others too.