I haven't thought about this in a while...
First, the ground rules:
1) Looks are great and all, but really, there will be 15,000 women on a beach in California tomorrow that I would find physically "hotter" than anyone on this list. But that doesn't matter for this list. Not that the women below are unattractive or anything, but I need to have read an interview, or seen her on a talk show, something that lets me know that there's a brain behind the the looks, and an actual talent beyond reading lines in a script (for example).
I've seen too many flavor-of-the-minute actors and actresses on Letterman that can't carry a conversation past the amusing anecdote (covered in the pre-interview, of course) they've tried to memorize.
"So, {actress}, what have you been doing during your show's hiatus? Did you go anywhere?"
"Why, funny you mention that, Dave. I just spent 2 weeks in Scotland, and boy did this funny thing happen to me..."
You can see Letterman fidgeting with his blue card wondering when the damned commercial break is coming.
2) I've always been drawn to older women. Intelligent, experienced, a knowing twinkle in the eye. I dated 2-3 years older than me way more often than I dated 2-3 years younger. I married that way too.
Anyway, here goes.


Shakira - OK, of course I go and violate rule 2 right away, but this in the only one on this list younger than me. Intelligent, talented, funny, ass and legs from the gods. And Ojos Así is one of the greatest songs of all time.
Shakira Isabel Mebarak Ripoll (Arabic: شاكِرة ايسابل مبرك ريبول ) (born: February 2, 1977), known simply as Shakira, is Colombian singer-songwriter, musician, record producer, dancer and philanthropist who has been a major figure in the pop music scene of Latin America since the mid-1990s. She is a native Spanish speaker and also speaks fluent English, Portuguese, Italian, and some Arabic. ... According to the United World Chart, Shakira is as of 2008 the 4th most successful artist so far for the last decade, in terms of single sales. She is also the only artist to have two songs in the top ten of the most successful singles since 1999
Seriously. How do you top that?

Tina Fey - First woman head writer for SNL. Wickedly brutal humor which really shone through when she started doing Weekend Update, instead of just writing behind the scenes. The mysterious scar. The horribly bad Greek middle name. The nerd chic thing she rocks. Oh yeah.

Jodie Foster - Intelligent, talented, strong. And OMFG that jaw and those eyes. It's ridiculous how beautiful she is.

Maura Tierny - The sad eyes just suck me in. The protector instinct kicks in, I think. She was a fucking riot in News Radio. Lisa Miller was one of the greatest sitcom characters ever, and that show was chock full of them. I've crushed on her ever since. She's probably the most private of all these people, but every interview with her I've read has been interesting. Also, TJ's wife used to play Barbies with her when they were kids in Boston. I don't know what that has to do with anything. Maybe they played doctor too...

Holly Hunter - Great smile, great voice, great actress, funny. What did David Strathairn say in The Firm? "I love your crooked little mouth." Yeah.
Honorable mentions: Sarah Silverman, Gwyneth, Uma, Sandra Bullock, Amanda Peet, Kelly Ripa
Here are more: Toast, Mike, Chris, Maurinsky, Tart