the not so nice ones:

• if there was a girl who had your personality, and looked like So-and-So, she would be perfect
• something like, "guys love girls with glasses" [of course, being sarcastic]

the nice ones:

• your dimples are amazing [I only have one dimple, but I will take it]
• you are so beautiful that I am simply surprised that you still have the capacity to be flattered after all these years
• you have beautiful skin (x2!)
• if there was an "I like you" button on facebook, I'd press it for you.
• so many good lookin girls at home with no dates. guys never realize this. I remember being in high school thinkin all the pretty girls had dates every Friday. that's a myth.
• you're very good at reading out loud [plus something about how I would be a good teacher, because of this skill]
• you have a good taste in patterns
• I'm glad that you're concerned with modesty and propriety. Girls that understand that guys need them to be that are gold.
• Every day, I set my standards by trying to be as ultra-frick-awesome and sexy-fab as YOU. None other than you. And I thought you should know.
• you're too cute for your own good
• you are the cutest thing on earth
• i LOVE to read what you write!