Among all the erectile dysfunction drugs discovered till date Viagra remains the undisputable king as the drug has been proved immensely capable of working against male impotency which have wreaked havoc in the life of millions of males across the world. On the one hand, while Viagra popularity has made Pfizer, its manufacturer incredibly cash rich, the rival drug companies have reached the threshold of bankruptcy as their products can no longer compete with the sheer efficacy and competency of Viagra power.