Salad greens: the options are (almost) endless! There's kale, spinach, watercress, mesclun, iceberg, and more.
If you're wondering which is best, the answer is: it depends.
Salad greens vary mightily in their nutritional profile and health benefits. But other factors may influence your choice on any given day, such as whether you're eating them pre or post-workout, as well as what the season is. And since nothing kills your intentions to eat well like monotony, having a rotation of favorite salad greens is a better idea than always sticking to one type.