Before going any further I must state that I am a happily married man with no intentions of leaving my wife. With that said, now I can tell you that I go ga-ga over Billie Piper. She started her career as a pop singer and released a few albums including The Best of Billie, an import that can easily be purchased here in the U.S.
She went on to win the role of the character that put her in every geek's heart (including mine): Rose Tyler. Rose was the first companion in the revival of the classic science fiction series Doctor Who. Rose was also the first companion to tell the Doctor that she loved him. In the classic series, love between the Doctor and his travelling companions was never revealed.
She has starred in a number of other productions, including the series Secret Diary of a Call Girl, and productions such as Much Ado About Nothing and Mansfield Park.
Why do I like Billie so much? Firstly because she's cute. She's also a very good actress and appears to be able to cry on cue. She's both funny and dramatic in the roles I've watched her in. She's also a pretty decent pop singer.
The bottom line is that if Billie Piper is in a film, TV series or anything else, I'm going to try and see it.