The weird thing is, I was considering starting this thread earlier today to mention my crush on GilgameshWulfenbach.
There is a case to be made for Baron Wulfenbach, too, though he is a tad old.
Amen to that. I’ve always been fond of the “wrench wench” type.
If we’re including non-animated comics, I’ll add Celia, from Piled Higher and Deeper. I mean, she’s nearly as nerdy as I am.
And I’ll also add Miss Kyle, from PS238. She’s a superpowered schoolteacher, what’s not to love? And from the same author, Piffany, of Nodwick.
You’re weird? I’m weirder.
Try having a crush on Rock Lee. How’s that for weird? 
Animated characters that struck me as hot… what was the female lead bunny from “Who framed Roger Rabbit?”… My favorite line from the movie came from her: “I’m not bad, I’m just drawn that way…”
Of course human / toon sex would be impractical at best… I mean their eyes stick out 18 inches when surprised or attracted… I could NEVER compete with that!
FML
Man, I had such a quivery thing for Aquaman when I was in jr. high. I felt guilty just reading his comic books. Almost the same level of lust for Daredevil.
Peter Pan has been mentioned twice already, phew! I never saw it till my early teens.
Otherwise, by the time I started noticing *cute *boys - I was too cool for cartoons. Now they all look like little children, even Gil. Baron Gilgamesh grates on me (he’d be back in his workshop far too soon if you get my drift).
Oh geez, I’ve always had a shining to the animated wimmin-folk. Here’s a list of what I can recall off the top of my head:
Erin Esurance
Jasmine
Ariel
Rei from Evangelion
Narusegawa from Love Hina
Katara from Avatar
Rukia from Bleach
Some aren’t 18 in their original series, which does squick me out a bit. Oh well. From what I gather, smallscale ephebophilia, animated or not, is the norm. (Acting on it is a different story)
Sweet jesus yes. That episode when she’s a lounge singer… >_<
Jessica Rabbit - she’s still smoking hawt!
And Princess Jasmin, she was quite the looker when I saw Aladdin for the first (few) time(s)
Slappy Squirrel.
I am showing my age:
Wanda Kay from the Hardy Boys
Pebbles Flintstone (Teen Pebbles from The Pebbles & Bam Bam Show)
More recently Daria and Jane, I love them both.
You’ll have to help me on this one - I can only remember that she was either a collie or a shetland sheepdog, with long hair, and normally wore an olive trenchcoat. I think she was a reporter of some sort, but for the life of me I can’t remember anything else…
Dexter’s Mom from Dexter’s Lab.
Woman here.
Not cartoons so much as comics and videogames, but still:
Cutter from the Elfquest series (my very first crush).
Morpheus of the Sandman graphic novels.
And most of the ones Ferret Herder mentioned (Carth Onasi had such whiny charm)
I occasionally drool a little at the tall, dark and steampunk guys in anime but I can never remember their names.
Jessica Rabbit, of course – she sends out extremely powerful sexual signals. She’s drawn that way.
Although, if I had to spend time with any of them, it['s the Mary-Ann-or-Ginger Effect, and I think a lot of guys would agree with me – the one to go to is Velma from Scooby-Doo. All those lesbian runors are simply the result of jealousy.
April O’Neil from the original Teenage Mutant Ninja Turtles series. There was something about that yellow jumpsuit.
Rogue from the X-Men animated series of the 1990s.
Minerva Mink from Animaniacs. Raaaawr!
And for me, I loathed April, because I always had a crush on Michaelangelo. What can I say? I’m a sucker for a good sense of humor. The only time my devotion waned was during the second movie, when Raphael was hurt… there’s something about a wounded man that’s just so appealing. 
I can’t believe nobody mentioned Princess Daphne from the Dragon’s Lair game of the 80’s. Sexiest Animated Babe EVAR (yes, with an AR!).
Also, all these mentions of Peter Pan, but no Tinkerbell love?
Penny here as well, in my younger days. Now, just her voice when I’m not looking at the TV (taken apart from the image of a little girl, it’s obvious she’s voiced by a sultry woman!)