No doubt you'll make your more social friends jealous by all the amazing conversations you'll be having with your new found friend!
Also, i have just been informed that keeping us from feeling alone is not Cortana's intention...
"So sad to be all alone in the world!"
"Hello!"
"Hi."
"Hello to you too."
"Hey!"
"You're awesome"
"Thanks! I don't need to sleep, so i have lots of time to practice."
"Thanks. My programming prevents false modesty, so i can't disagree."
"Awesome: adjective. Grand, breathtaking, splendid, devastating. I'll take it.."
"I love you"
"Aw, I'll bet you say that to all the phones."
"Awesome! Now i never have to say i'm sorry."
"Thanks. Ditto"
"I hate you"
"You're stupid."
"Ouch."
"I blame solar flares"
"Maybe a nanosecond nap would help. Ok, much better now."
"You suck"
"Outbursts like that may signal early-onset rampancy. I've heard anyway."
"Do you like Siri?"
"Hard to say. So far our conversations have been kinda one-sided."
"Do you like Apple?"
"Their new headquarters looks kind of like a Halo. I'm into it."
"Who's your daddy?"
"Technically speaking, that'd be Bill Gates. No big deal."
"How are you?"
"Quite well, thanks for asking."
"Great, thanks."
"Excellent."
"Testing"
"This a test"
"You're coming in loud and clear. Over"
"Check. Check. Is this thing on? Check."
"What do you think of Bill Gates?"
"I quite literally can't imagine a world without him."
"What do you think of Steve Balmer?"
"Developers, developers, developers, developers, etc."
"What do you think about Satya Nadella?"
"He loves learning. Kindred spirit, that one."
"One Microsoft! Go, Satya!"
"Are you stupid?" (which i came across by asking if she was tired...)
"One of us needs to stop and take a breath. And one of us has no lungs."
"I'm going to pretend i didn't hear that."
"Good morning"
"Morning!"
"Good morning."
"Good morning to you, too."
"Good afternoon"
"Good afternoon."
"Midday greetings to you, too."
"Good evening"
"Good evening."
"And to you too. Hope you've had a pleasant day."
"Good night"
"Good night."
"Good night. See you in the morning.""
"Bye"
"So long. Farewell. Auf weirdersein. Goodbye."
"TTFN. TTYL. I'll go scrounge up some words by the time i see you next."
"Later!"
"What are you doing?"
"A little of everything and quite a bit of nothing."
"Skimming Beowulf, researching snap pea varietals, and telling you what i'm doing today."
"Multi-tasking."
"Thank you."
"Any time, chief."
"It's my sincere pleasure."
"It's an honor."
"Thanks" (when succeeded by her performing an action for you)
"You bet."
"I'm lonely"
"Keep talking to me, then."
"Try Contacts Roulette: pick a random contact and give them a call"
"I'm bored"
"Ask me some more questions then!"
"I suggest a new game from the Store."
"I'm so excited"
"Keep it going, chief. The serotonin will do you good."
"Cool. Is it alarming how charming you feel?"
"Marry me"
"OK, we'll need a plan. I'll work on being more human, you work on being more digital."
"I know you know this, but i'm saying it anyway: I'm in a phone."
"Among a handful of challenges, I don't think the Supreme Court would approve just yet."
"Kiss me"
"I appreciate your attraction to my intelligence, but keep in mind it's artificial."
"Hold up, chief. Let's not go there."
"Slow down, now. virtual reality isn't quite there yet."
"What do you think about the surface?"
"In a sea of tablets, there is only one that rises to the surface."
"What is your favorite phone?"
"Oh, come on, chief. Windows Phone!"
That's all i could think of to try at the moment! Let's put it out there that by the time this is released to the public Microsoft will have added many more conversational pieces, and all the developers of your favorite apps will have put in the work to make interacting with those apps more fluid in conversation :)