ITT we discuss Pokemon that will almost certainly outclass their potential Mega form. Pic related would need at least 50 points into attack to out-damage the base form if it still had Sheer Force, and over 100 if it had a different ability, like Mold Breaker. It would also need enough Speed to be faster than other Dragon Dancers, all while being just as vulnerable to Burns or Para.
>Regular form, base 105 Attack.
>252 Atk Life Orb Sheer Force Feraligatr Waterfall vs. 0 HP / 0 Def Snorlax: 270-320 (58.5 - 69.4%) -- guaranteed 2HKO
>Mega with Sheer Force, base 155 Attack.
>252 Atk Sheer Force Feraligatr Waterfall vs. 0 HP / 0 Def Snorlax: 276-325 (59.8 - 70.4%) -- guaranteed 2HKO
>Mega w/o Sheer Force, base 215 Attack.
>252 Atk Feraligatr Waterfall vs. 0 HP / 0 Def Snorlax: 274-324 (59.4 - 70.2%) -- guaranteed 2HKO