Here are a few of my favorites, though there are so many good ones it is hard to choose the best:
"This lipstick is mine. Always, Anna."
"This is the bum Gloria is in love with."
"From Billy Smith, To Thelma, my SweetHeart."
"In the sun."
"1968. Esther. New teeth."
"I think I'll marry this one. He is beautiful and brings out the best in me."
"Aint I a stinker?"
Doesn't it make you want to turn over every photo that you find? See more of his Talking Picture treasures archived here.