So... the whole "Imaginary Casting" thing has its appeal. I got sucked in BIG TIME. So here are the people I came up with to go with each character. I'm not saying they'd be perfect; these are just people that sprang to mind.
I like Rachel Hurd-Wood. Last I saw her was in "Peter Pan," so when I saw some recent interview footage I was surprised at how much she's grown up. She'd need to drop the British accent, but I think she'd be great.
Jace is really difficult. As much as Alex Pettyfer is a fine actor, I think he's a bit too... male model-ish? A bit too... *something*. He just didn't seem like Jace to me. I would LOVE it if Nicholas Hoult could pull off the blonde look. He has that swagger, that arrogance mixed with flashes of vulnerability, and does sarcasm quite well. He too would have to lose the British accent.
I looooove Alec, which is why this was so hard for me. And the Gaspard guy everybody keeps mentioning seems way too angular. I mean, I know that's what Cassandra Clare says she had in mind, but he doesn't match what I had in my head. I like Ricky Ullman for Alec, though he'd have to be waaaay less smiley than his normal demeanor.
EDIT: Now I'm really liking Daniel Henney. He's half Scottish, half Korean, but more importantly... he's 100% HOT. Plus I think he could really rock the glitter!
I'm going with Adam Lambert, because of this picture.
When I first read the description of her, I thought immediately of Megan Fox. After getting to know the character better, I much prefer the popular suggestion of Summer Glau.
Another difficult one. I wasn't opposed to the popular choice of Kristopher Turner until I looked at his IMDB page and realized he was nearly 30! I think David Henrie (yes, the older brother from "Wizards of Waverly Place") with some glasses would work.
Totally love Jurnee Smollett. Hear hear!
David Sutcliffe immediately popped into my head. No, that's a lie. Actually, what popped into my head was "Rori's dad from 'Gilmore Girls.'" Then I looked him up and found out his name was David Sutcliffe.
Viggo Mortensen = spot on. Although Ralph Fiennes could do it well too. But there could be some law I don't know about that says once you portray an evil villain for a major fantasy series on screen you're not allowed to do another.
So there you have it... a few of my choices. But I like seeing what everybody else thinks!!!