Miyazaki Ui 宮崎羽衣 gets my vote as prettiest of all active seiyuu.
The characters for Ui are the same as for the mythical hagoromo, the feather mantle 羽衣 of a goddess. There is a legend that a mortal stole the mantle while the goddess was bathing, trapping her on Earth. Ui's mother gave her the name after a trip to the place where the event is supposed to have taken place (Mihono Matsubara).
This year, Ui-chan (also known as Ui-ui) went to her grandparents' place in the country, in Ibaraki, north of Tokyo, to see in the new year with them and her cousins. Her grandfather, who is convalescing from an illness, had a banquet of sushi brought in. She and her cousins embraced as she left, sad to part again.
But once back in Tokyo, she found she had a cold. There was no heater on the second floor of her grandparents' home, where she slept. She ended up spending four hours under a futon in Tokyo, shivering uncontrollably. But she is off on another trip tomorrow.
Ui says she wants to "shrink the distance" between her and her fans this year, by means of her fan club, Ui Love You. She has a fairly active photo blog, all the photos here were posted there over the past few days. She has done a lot of radio work, and is known as a "dumb blonde." She says she never throws anything out and has a very messy room.
Here's her home page. She was born on 23 August 1981 inTokyo. She was Kirino in Gift ~Eternal Rainbow~, and Iroha in Sumomo mo Momo mo, and did a nice job starring as Erisu in Night Wizard. Japanese Wikipedia. English Wikipedia. Anime News Network.