I love how low key (tonally, not musically) the credits theme of Luigi's Mansion 1 is, it gives me less of the "you're the ultimate hero! woo! let's celebrate, peace and prosperity are here!" vibe that I get from most Mario credits, and more of a "life's back to normal, let's go back home and get dinner." vibe, which has always been a more rewarding style of ending to me.