If you are writing a paper on this topic, it might be interesting to argue that the love that Odysseus and Penelope share is not the same. Let me explain.
Penelope has been a model of faithfulness. There is no doubt about this. She waited twenty years and she was faithful all throughout. She was under enormous stress to marry one of the suitors and all indicators pointed to the fact that Odysseus was dead, but she still held out in hope. She even concocted various schemes to ward off the suitors. In a word, her love for Odysseus was true and it showed in her faithfulness.
When it comes to Odysseus. His twenty years was a bit more complicated. He stayed with Calypso for seven years as a love slave - somewhat willingly. Eventually he had to go through great struggles to get home, but the Calypso episode could be seen as a blemish.
In the end, I suppose that you can say that Penelope and Odysseus share the love that is found in marriage and it is evidenced in sacrifice.