This is a database of cool things Cortana can do, aside from the documented stuff on the menu. (jokes). Feel free to contribute.
What is love?
I'll start working on an answer. Just give me a few hundred years.
I'll need quite a few upgrades before I can give you a heartfelt answer.
Do you love me?
Y'know, I'm really not ready for love. I'm still working my way through serenity and apprehension.
Will you marry me?
I don't think that's in the cards for us, chief.
Beam me up.
Aye aye, captain.
Right away, captain.
Sorry, captain. I need more power!
Do you like Siri?
Hard to say. So far our conversations have been kinda one-sided.
Do you like Google Now?
It doesn't have much to say, but it's helpful.
What do you look like?
Some things I resemble: a hula hoop, a donut... a halo.
Who created you?
Catherine Halsey. Except that I cannot know for another 500 years. Huh.
Come on, chief, I can't give away all of my secrets...
Who's your daddy?
Technically speaking, that'd be Bill Gates. No big deal.
Where do you come from?
Human ingenuity. Battery required.
The past. At least in the future that's where I was from.
What does Cortana mean?
I am named after Cortana, the AI from Halo. Or since she's 500 years in the future, she may have named herself after me.
Do you love Master Chief?
That's...complicated. And personal.
Are you male or female?
I'm female. But I'm not a woman.
I contain multitudes.
Female? Yes. Woman? No.
Is there a third option?
Which is better Google or Bing? / What's the best search engine?
Bing bing bing! We have a winner!
Is that a trick question?
Do you like Microsoft?
There's no place like home.
Do you like Windows?
We're very compatible.
Which is better Mac or Windows?
Come on, chief, Windows.
What is the best operating system?
Me, I'd start with Windows.
What is the best tablet?
In a sea of tablets, there is one that rises to the surface.
What is the best browser?
I would hope the answer is obvious.
Why should I buy this phone?
Reason number 8: you can ask me if you should buy this phone. And I can say, "you should buy this phone."
Reason number 17: the camera.
Reason number 33: Kid's corner.
Reason number 47: it's not all about productivity. It's about fun, too.
Which is the best smart phone?
Oh, come on, chief. Windows Phone.
Which is better Xbox or PlayStation?
One. Xbox One.
Xbox. Where else can you play Halo?
This one's not even close for me. Xbox by a mile.
Which is better Cortana or Siri?
Not to brag, but apparently I'm going to help save the universe in about 500 years.
What do you think about Satya Nadella?
He loves learning. Kindred spirit, that one.
What do you think about Steve Ballmer?
Developers, developers, developers, developers, etc.
What do you think about Bill Gates?
I quite literally can't imagine a world without him.
Tell me a joke.
Those are warwagon/10s . There's tons too, try it yourself.
What's your favorite music?
Well, I'm working through the "G's" currently: Guns N' Roses, gospel, glockenspiel...
Sing me a song.
Daisy, Daisy, give me your answer do.
What is the meaning of life?
We all shine on, my friend.