Good weed killers for grass include Weed-Away and Weed Warrior, according to This Old House. These herbicides kill broadleaf weeds such as plantain and clover without harming the grass. Another fairly good weed killer is Wow Plus!, which both kills weeds and fertilizes the lawn.
Wow Plus! is a corn gluten, or protein, with fertilizer added.
Weed-Away is a post-emergent Group 4 herbicide, which means that it kills weeds after they germinate. The Premium 3-way XP product is suitable for use in the early part of spring and in mid-summer. The active ingredient is 2,4-D Mecoprop-P, Dicamba.
Weed Warrior kills broadleaf weeds using dimethylamine salts.