“Sorry, no time to stop. We’re fleeing the Terror Horde. They’ll be here in five of your years so you’ll want to get out of this solar system before they arrive.”
10…9…8…7…6…5…4…3…2…1…
Meesa on a diplomatic mission!
“Send more Chuck Berry.”
We are of Peace. Always.
“Hi guys, nice to meet you. Eh, you obviously can’t be aware of this yet, but there was a dreadful accident at the galactic core about 60 thousand years ago, and the blast wave, well, we’re travelling about 50 years ahead of it, looking for stragglers. We can’t stop, but here’s some plans for you all to look at. We recommend the collective upload option, you don’t really have enough time to move your planet, sadly. Best wishes, The &&&^&&&&@”
“Have you heard The Good News?”
“We hereby claim this planet in the name of Its Most Xfisthian Majesty, Zzymlyijak XXXVIIth, Overbeing of the Orion Arm and the Perseus Arm, Conqueror of the Outer Rim Territories and Vanquisher of All the Globular Clusters.”
“In our obscurity, in all this vastness, there is no hint that a powerful and rapacious Space Empire will come from elsewhere to spare us from racial suicide by killing us all off before we can do ourselves in.”
Here is a copy of “The Watchtower”. Be sure and read it as it tells everything that is going to happen.
We come in the name of the One True Faith, as represented on Earth by The Islamic State.
Take us to your Mormons.
“I am Lrrr of the planet Omicron-Perseii VIII.”
Congratulations, sapient beings of Sol III! You have been approved for Probationary Membership in the Galactic Federation!
Benefits of Probationary Membership include:
[ul]
[li]Technical assistance in many fields, including the development of true spaceflight.[/li][li]Opportunities for trade with other Probationary Members, Associate Members, and even Full Members of the Galactic Federation.[/li][li]Technical assistance in eradicating the dangerous infestation of bipedal primates which has been observed on your planet.[/li][li]The opportunity to advance to Associate Membership, and eventually even Full Membership in the Galactic Federation.[/li][/ul]
At last, people of Teegeeack, I have returned. Notice how my spaceships resemble your pitiful DC-10s. Now, kneel before Xenu!
“Know any SKYNYRD?”
"Zeep-zorp, BABA-BOOEY BABA-BOOEY!!!"
Actually, that would be one of the best! 
“At last, Earth! Home of the great warrior Propinix! You are the only hope the galaxy has against the coming of the Kifivathi. Save us, O Earth!”
my daughter chimed in:
“New phone. Who this?”
Good news! That whole afterlife thing is real.
The bad news? That whole God/Satan thing? You’ve got that part backwards.
Neanderthals! What have you done with our precious Neanderthals??!
Amway.
CandyGram.
Space shark.