How do you say "mejor hago x en vez de..." in English?
I don't kwon if I was clear. In Spanish you can say "mejor" to compare to things, but it has other use. For example, you're going to eat an apple, but you say "mejor como un plátano" Is there a English equivalent for the expression?

Question

Answer

When you have two or more options, and there is one you prefer the most, you can say I`d rather, which means "prefiero". In Spanish we use the term "mejor" not only as a comparative but to express some degree of preference. In this case you should say "I´d rather eat a banana." That´s to say you prefer the banana and not the apple you mentioned in your example.
Other example is: 
 - Do you want to go to the movies?
 - No, I´d  rather stay home.

-¿Quieres ir a cine? 
 - No, mejor me quedo en casa.

Answer

Qual es mejor Emelec o Barcelona?

Answer

Better, like a Plantain

Answer

( It's) Better to eat a banana than an apple.

Answer

The apple is better than the banana.
or
I like apples more than bananas