Penelope and Odysseus both show tremendous willpower and emotional endurance. Just as Odysseus exhibits these qualities in his struggles to return to Ithaca, so does Penelope in her enduring of the Suitors. In addition, they are both very intelligent, and they both show a particular gift for trickery and deception.

If there is one quality that, more than any other, makes Odysseus stand out among the heroes of Greek heroic literature, it is his cunning. Consider, for example, his encounter with Polyphemus or his deceptions back in Ithaca, carried on with the aid of Athena. In this quality, however, he is actually very well-matched by his wife, who also shows exceptional resourcefulness and cunning. Through trickery, she is able to hold off the Suitors for years. Furthermore, consider her reaction to Odysseus's return: rather than trust that this is her husband, she tests him, feeding him false information to see whether he'd catch the deception.

In The Odyssey, Homer's epic classic of courage and strength, the subjects of your question are the main characters.

Odysseus is the hero of the story, and in the classic style he is a man with the qualities of strength, skill, determination, moral responsibility, intelligence, loyalty and adaptability. All of these qualities come into play in his adventures from the time he leaves home until his return.

Penelope, his wife who is left behind in less than ideal circumstances, is stronger than any other female character of the time. She too demonstrates many ideals that surface during the struggles she faces - strength, courage, moral strength, intelligence, loyalty, etc...  Most of these are evidenced in her handling of her suitors when it appears that her husband will not return.

That being said, the similarities that stand out the most seem to be in the areas of strength, moral responsibility, intelligence and loyalty.