When you first see the escort, best Wow factor.

[Sol Tee Nutz]

This is just at the very first minute(s), no sex yet.

Mine would have to be Natascha from Good Girls a few years ago, when she opened the door and was in white bra and panties and her overall cuteness.
Note: The wow did not go away for awhile.

 

[Numerati]

Amelie of then Independent Network. She was my third SP I saw in the hobby. I was more into brunettes but she was blonde. She was naturally beautiful. I was literally floored. Second time around was Ophelie of French Courtesans/FKS/Indy. Third time was Amber of MGF. Fourth time was Sophia of MTLGFE. And Megan of Vogue.