Sodapop: Your smile. You'd always smile for everything and he loved how happy you were. Seeing you smile made him smile and his smile is just lifesaving so you'd do it a lot.
Steve: The way you dressed. You didn't care what anyone else thought about you. You'd wear jeans and a t shirt and it would make you happy. Most of the time it was a DX t shirt and Steve loved that!
Dally: Your kisses. Even though he'll never admit to loving anything, he loved you and your kisses and how passionate they were.
Two-Bit: Your laugh. Two-Bit is a goofball, but it's because he always wants to hear you laugh. He'd do anything to hear that laugh of yours.
Darry: Your love. He loved you so much and he wouldn't be able to live without you, so you made sure that Darry knew just how much you loved him.
Johnny: Your shyness. Johnny was the shyest one of the gang and you were the shyest one of your friends. When you guys kissed you would be blushing for hours on end.
Ponyboy: Your smarts. He loved how much you cared about your education and how much you wanted to make sure to get good grade. You did all of this just to make sure that when you're older, you'll be with Pony in college.