As a big, fat, stinking homo, I think I'm obligated to rank the men first. It should go without saying that this list is shallow as hell.
THE BOYS:
1. Prince Naveen, The Princess and the Frog - Damn! Did someone turn on the heat in here? I'm getting a little toasty!

Seriously, though, Naveen was gorgeous. Those dimples and that smile... Plus, I love his carefree attitude. His accent isn't the hottest in the world, but, if it's coming from that face, I can live with it.
2. (Adult) Hercules, Hercules - It's really his vulnerability that endears me to him most of all. Which is ironic considering he's, you know, practically immortal.
3. Aladdin, Aladdin - Yes, yes. The list wouldn't be complete without him, would it? What is it about him that's so attractive? I blame the open vest/no shoes thing. That's a lot of exposed flesh.
4. Tarzan, Tarzan - Dem abs! Give him a haircut and a bath and he's good to go!
5. John Smith, Pocahontas - He's pretty, but GOD is he dull.
6. Prince Eric, The Little Mermaid - I think the scene where I find myself thinking him sexy is the scene where he rescues Max from the burning ship. Any man who loves his pet that much has to have a good heart. The fact that he's good-lookin' to boot is just an added bonus.
7. Gaston, Beauty and the Beast - Admit it. You'd let that hair-chested bastard mount you like a stag.
8. David Kawena, Lilo & Stitch - Hunk of burning love, indeed. Yeah, he's dull. But he's good eye-candy.
9. Frollo, The Hunchback of Notre Dame - That voice is pure sex. Don't look at me like that.
THE BABES:
1. Esmeralda, The Hunchback of Notre Dame - Whoah. Just...those EYES! Gorgeous. Her luscious hair and womanly physique are very sensual and sexy as well. She's very much a woman, not a girl. It's sad how little the company gives a shit about her. If Mulan can be a princess, why not Esmeralda?
2. Princess Aurora, Sleeping Beauty - Classy. Elegant. I've always thought she was the most beautiful of the original princesses.
3. Jessica Rabbit, Who Framed Roger Rabbit? - Does she count? She better! Do I really even need to SAY anything? She's got that femme-fatale noir thing going for her. And Kathleen Turner's sultry voice adds so much to the character.
4. Helga Sinclair, Atlantis: the Lost Empire - So glad someone else listed her, too! Again, much like Jessica, she has that femme-fatale film-noir moll thing going for her. And that's sexy.
5. The Evil Queen, Snow White - In her QUEEN form, that is. Who says evil isn't sexy?
6. Katrina van Tassel, The Adventures of Ichabod and Mr. Toad - Essentially Cinderella before Cinderella. But I think she's better looking and her personality is a little less saccharine.
7. Megara, Hercules - Yes, I do think she's sexy. She's actually got a head on her shoulders. And I love her cynical personality. Her voice is very mature as well.
8. Ursula, The Little Mermaid - Not Vanessa. Ursula. You heard me. She may be big, but she's got PLENTY of sex-appeal. She's a vamp! Come on! Shakin' them ta-tas all over the place and gyrating during Poor Unfortunate Souls.
For some reason, I, too, can't see many of the Disney Princesses as 'sexy.' They're just so...corporate and sanitized to be thought of sexually these days. It's kinda squicky, actually.