Do You Get a Better Workout Alone or With a Buddy?

With my busy schedule between work and family, it's hard to coordinate exercising with a friend. So I end up sweating it out on my own most of the time. I do love working out with a buddy though, so at least once a week I try to plan fitness dates. If I exercise with someone who loves to push themselves, it really motivates me and I end up getting a better workout than if I were solo. How about you?