First off. the most important place to start in addressing the matter is that it depends on what phase of their textbook narc cycle they’re in.
The Idealization Phase
In the idealization (or love-bombing phase) the narcissist will look deep in your eyes with the most euphoric bewilderment that someone so incredible even exists… they are god-smacked by your mere presence (or at least appear to be, as we now know this was all a manufactured presentation to hook you), and from this seemingly awe-stricken place, with the light of all the stars in their eyes, they will say things like the following…
“You are the most beautiful girl/handsome guy I have ever seen”
“You are so amazing; I wish there were more people like you in the world”
“I want to be open with you like I’ve never wanted to be open with anyone else before”
“I knew I wanted to be with you from the first time I laid eyes on you”
“I feel so lucky that you are giving me your time”
“I just want to better myself every day to be the best for you and for the life we are building”
“No one could ever compare to you”
“I’m so afraid to lose you”