How about in the pilot when Adam says "I don't care what our parents think of us. All that matters to me is what you think and how you feel. I know how I feel because I've never felt this way about anybody before."
Also, I love the phone conversation Adam and Jewel had. Adam was just too cute trying to play it off in front of his mom like he was talking to some guy named Eric.
Jewel: "I love you."
Adam: "Really."
Jewel: "I really, REALLY love you."
Adam. "Great."
I love the ones that have already been mentioned, particularly
"I loved touching you, and you touching me. I love everything that happened." How does Jewel not melt when Adam says this kind of stuff to her?!