I say both, they both motivated eachother along the way, whenever frodo was down..and ready to give up, sam was there to help him along the way, encourage him to keep going, and goes the same for sam, when sam was down, ready to quit, frodo helped, encouraged him along, id say they both are heros, they both carried out the ring to mordor, they both deserve the hero titles, they wouldnt of made it if they didnt help eachother out, although at times frodo got a little evilish when it came to the ring, sam told him to fight it, and frodo snapped back saying "i know what i must do sam, the ring was intrusted to me, its my task, its my own" it didnt let sam down though, he still had faith in frodo, and frodo had faith in sam, and together...they worked together to get to mordor and carry out the task, so to me...both of them
Go frodo and sam!