Goa is undoubtedly better when it comes to water sports & adventurous activities...
But if you are a beach lover & want to experience some good beach scenic view,Gokarna is surely a must see
The beaches in Gokarna are a way more beautiful as compared to Goa this days..
& you can even visit Murudeshwar Temple if going to Gokarna
Depends on what you seek. If you want to party and don't mind crowded beaches, Goa is the place. If you're looking for more secluded beaches and a peaceful atmosphere, South Goa or Gokarna are your options.
If you are going alone gokarna would be a better choice as you would meet peaceful and like minded people and gokarna is damn beautiful . After which if u have time can travel to goa for a day ..Goa is best with a partner or a group of friends .