As the moderator of the gameboy strategy section, it frustrates me to be seeing so many Gyarados with flamethrower and thunder and surf and ice beam... *cries*
Gyarados- [atk + / sp.atk -] @ salac berry
EV: Atk and Spd, perhaps mix in a bit of sp.def if you want
-taunt
-dragon dance
-hp flying
-earthquake
it's not about the 140 special attack stats... it's about the 370 physical attack power with the ability to dragon dance, and a nice STAB HP Flying. (however: Metal Chicken > Gyarados)
Milotic is limited? =/
Milotic- [sp.atk or sp.def + / atk -] @ leftovers
EV: Sp.atk, Sp.def and HP
-recover
-toxic
-surf
-ice beam
(feel free to insert mirror coat or light screen over one of the 2 attacks)
High HP, high sp.def, and recover... use toxic, and recover SPAM. Attack at the right time, and you get a dead sp.attack in front of you. It can block even thunderbolts very well as long as it's not STAB. Actually, Milotic is used more than Gyarados as there aren't that much special sponges if you don't want to use Blissey. Milotic's superior ability to special sponge makes it very worthwhile to have on a team. Milotics with uncommon movesets can even hypnosis at times, calm mind up then sweep.
However, evil egg of doom > Milotic, lol... just like how it's "physical counterpart" is screwed by evil egg's best friend.
They're both equally as good, and useful in their own ways.