Like other's I have had many.  
A few years ago I discovered Dana Vespoli on Randy West's "Up and Cummers 121".  I think he is half Irish and half Thai.  Amazing body and face and a pro under Randy's tutelage. This might have been her first shoot so she was young and fresh and very natural.   I then discovered her again on "Lusting Teens" by ATM Inside, after she was in the business a couple of years so she is more professional looking but still has that special quality that makes you run for the lube.  I treasure these DVDs and when I'm having a bad day (or a good day for that matter) I will pull these off the shelf for relief.  
However, around the same time, I discovered BrunoB and one of his first videos with a young blond Quebec girl named Christine.  Wow.! I can't be the only one who relied on her for frequent relief during those years? She was very young and had amazing tits, a smoking body, and a GND look that made me melt.  I always wondered what happened to her and whether she made it beyond the Quebec scene?  
More recently, I have been enjoying the company of Evelyn Lin in Mark Ashley's "Teen Machine Vol 1".  A fresh young Asian who is near perfect.
But my biggest vote goes to a very recent discovery:  Amia Miley on Jules Jordan "Beach Patrol 2".  Just an incredible star who was born for porn.    She has a spinner body, perky natural tits with puffy nipples and a beautiful pussy.  Just can't get enough of her; but believe me I try...