Pesky Insurance Agents

How much life insurance does one really need? I sometimes get so tired of insurance agents who keep calling me up and pushing their life insurance rates. I have heavy commitments every month as it already is and I do not really need to over burden myself further by buying more expensive life insurance policies. After all, reports have said that as long as you have no children of your own, there isn't much point in stocking up on life insurance policies as no one would really stand to gain from your policies.