Because this is more interesting than it should be, in no particular order:
1. Lady Macbeth (Macbeth, Shakespeare): No particular portrayal. As long as she's not played by an incompetant minger I will get the hots for her. It may be noted that whilst this is in no particular order, given that she has no fixed image, she could be considered the prototype for some of my other selections. She's sexy, bad and fairly mad. A seductress. I might kill for her. I might be lulled into a false sense of security by her so her husband can stab me up. Depends on whose fantasy this is.
2. Lila Morgan (Angel, TV series): A real woman. Her favourite colour is green, she looks good in diamonds and she likes riding around in expensive limos. Fantastic romance/sex affair with Wesley - far hotter and yet more touching than any other relationship in that universe. Evil, lovely. See above.
3. Jessica Rabbit (Who Framed Roger Rabbit): Same as Mikey, it is the voice. But also the big cartoon boobs, the dress. The fact she's evil (I'm not convinced by the "I'm not bad I'm just drawn that way" line).
4. Heather McLeod: It may look like I've pinched some of Mikey's, but he reminded me of past passions. She walks down the stone steps with food and beer in a gorgeous dress, asks her hard-working man: "Pie and ale. Do you want it?" And the look says it all. She calls her husband "My Lord." She's beautiful and sweet. An exception to the 'evil' tendency.
5. "Saffron Reynolds" (Firefly - TV): Physically, wow. Just wow. Amazing figure, pretty face. Wenchy outfit. Plus - evil.
6. The Vampire Genevieve Dieudonne (Geek books by Jack Yeovil, aka Kim Newman) - Wiped from Neil, but also a historical masturbatory fantasy from my adolescence. She was designed to be such a thing by the Geek Lord Kim Newman. She appears in geek fantasy novels with original plots that tie together set pieces and characters directly lifted from every cult movie ever. She is one of the few original (well, ...ish) characters in the books. Not evil, but, you know, vampie.
7. Queenie (Blackadder 2) - Gorgeous, insane, and very very bad for me. Plus her nose is pretty.
8. Gaia (Rome, Season 2) - Dark braided hair, great figure, revealing outfit, naughty demeanour and quite handy in a scrap. Combination of slave girl and evil mistress. Arrrgh, my loins, I'm in lust again.
9. Silvia (Brotherhood of the Wolf) - Monica Belluci being all of the above fetishes in one role. Including the giant cartoon boobs. Not that evil, per se, but ruthless enough. Really nearly all of the women in this film are eminently doable, but she stands out.
10. Lucius Vorenus and/or Titus Pullo - I'm not gay and neither are they. As long as we all understand that, we'll be OK.
Edit: Queenie now replaces Cheetarah. More than one cartoon woman is too many, and I have a massive lust problem with Miranda Richardson.