Final answer:
Neil and Gretchen are experiencing romantic love, defined by passion and intimacy with no commitment, while Armando and Jenny's marriage represents companionate love, emphasizing intimacy and commitment without passion.
Step-by-step explanation:
Neil and Gretchen, who recently started dating and have an overwhelming urge to be together and engage in sexual activity frequently, are experiencing romantic love. This type of love is characterized by passion and intimacy but no commitment. In contrast, Armando and Jenny, who have been married for several years and feel like they are each other's best friends, have a relationship that has evolved into companionate love. Companionate love is characterized by intimacy and commitment but typically lacks the passionate aspect of romantic love.