For Story shift Chara...
Default has two.
The normal, much higher likely chance one is "It's a magnificent day to die."
The secret one goes as follows:
"A magnificent day to comes to its end...Birds are still singing, ignoring the threat...And feeling the power, that's not even yours...BE READY TO SUFFER FOR EACH YOUR ABUSE."
For VHS Sans, he simply says "Better start running."
Sudden Changes Sans says "Don't be so nervous. After all... You're just going to hell."