Yes! You wanna go old school, Debra Winger in Cannery Row. For that matter, less old-school, Linda Fiorentino in The Last Seduction. I’ll two two of both.
Also some Angie Dickinson from Rio Bravo, please
Lucy Deakins from The Boy Who Could Fly:
Phoebe Cates from Fast Times:
Audrey Hepburn in My Fair Lady
Natalie Wood in anything, but especially West Side Story
Despite her nude scene Kate Winslet did absolutely nothing for me in “Titanic.” I’m sure a lot of it had to do with the fact that I hated almost everything about the movie except the special effects, including the horrible romance, the dialogue, the music, and the characters. She was nothing more to me than the latest starlet and I promptly forgot about her.
THEN I saw her as Iris Murdoch in “Iris,” gleefully indulging in sexual infidelity and Winslet hit me like a punch in the face, so sensual, so sexual, so alive. And that body, that wonderful, fleshy, sensual, warm, curvy, womanly, fertile body. I’m turning myself on just writing these words … (shudder)
I felt physical pain watching that character, so human, so alive, lose herself to Alzheimer’s.
Similarly, first saw Penelope Cruz in “Belle Époque” and I was much more interested in the actress who played her character’s eldest sister, I think it was Miriam Diaz Aroca. I think Cruz struck me as just too girlish in that role. She finally got my attention as Johnny Depl’s character’s wife in “Blow.” Fiery, voluptuous, hot. Her appearances in “Volver” and “Vicky Christina Barcelona” sealed the deal for me.
Salma Hayek as Frida Kahlo In “Frida.” There’s nothing about Kahlo that I find sexy, herself or her art, but there was Salma.
Oh, yeah. Kevin Kline is a lucky, lucky man.
Jenny Agutter as Nurse Pryce in An American Werewolf in London.
More times I fell in love with the actress:
Wait, let me revise that:
Juliette Binoche in Damage – especially when she’s having fun times.
Yeah, I know exactly the scene you mean. Wowza.
Another vote for Hayek in ‘From Dusk til Dawn.’ I speak with experience on that uh, cameo, because I had to peel my then-boyfriend’s tongue off the tv screen. 
Another vote too, for Heddy Lamarr. Another knockout: beauty ***and ***brains. Lamarr co-invented – with composer George Antheil – an early technique for spread spectrum communications and frequency hopping, necessary to wireless communication from the pre-computer age to the present day.
As for the male of the species, Robert Mitchum in his prime. Yowza.
Yes, but we’re talking about the characters here, not the actors. Did Lamarr play any notably brainy characters?
Delilah
oops. 
that’ll teach me not to read the op correctly the first time around. still say robert mitchum, tho - in any role.
“Night of the Hunter”? )(“Chiiiildrennn!”)
“Cape Fear”? (“Mmm…mmmm, counselor! She almost as juicy as your wife.”)
I was just reminded of my favorite Robin Hood - Errol Flynn. A swashbuckling, handsome youth, with a wink in his eye and a spring in his step. He nailed it and I loved him!
Olivia Hussey in Romeo & Juliet (lucky bastard!):
http://www.dempeaux.com/wp-content/uploads/2011/05/zeffirelli.jpg
Jane Seymour in Live and Let Die:
http://ia.media-imdb.com/images/M/MV5BNDk0NzcyNTg2Ml5BMl5BanBnXkFtZTcwMjk2NDk0NA@@._V1._SX640_SY431_.jpg
If I were in that pose, I don’t think my eyes would be pointing in the direction his are.