"Making memories with you" implies that spending time together and sharing experiences is a source of happiness and fulfillment.
"Is my favorite thing to do" emphasizes the special place that these moments hold in the speaker's heart. It suggests that the act of creating memories with their loved one brings them immense joy and satisfaction.
In essence, this statement celebrates the significance of shared experiences and the bond formed through the creation of lasting memories with someone dear. It highlights the value of togetherness and the happiness derived from these precious moments.