Meh...This is too close call...
Feraligatr hmmm...Earthquake, AT/WF, Ice Punch and Crunch/DD/something,
vs Gyarados Earthquae, AT/WF, Ice Fang/something else, DD...

Pretty much same thing, though I nowdays prefer Feraligatr more.
Gyarados wins by look and speed in my taste,
but neither won't faint with light teasing either.

Feraligatr.