Unanswered question in my head

A question arises in my head. It is about love.
Before I go any further, I would like to clarify that this question mark came to my mind as I watched too much dramas and have been a listener and counselor to quite a number of friends and even family members.

A friend told me there is neither right nor wrong in love. I strongly agree with that because feeling is certainly not something that one can control. Should one just sacrifice his/her own happiness for the sake of others or think about his/her own happiness but taking away other people's happiness? *perplexed*

Opposite or similarities? Which is better in a relationship? opposite attracts but some prefer to be similar.

I guess it is a case to case basis =)