Be honest 2 ladies and fellas

I would say communication if couples cant communicate then something is wrong in that relationship....Also communication is vital in any relationship whether it be Father/Mother Teacher/Student Doctor/Patient Parents/Children etc.....Trust is the foundation in a relationship.

i'll go for the communication too :D cuz if ure both communicating well. those misunderstandings and conflicts can lessen if u both understand each other (feeling and thoughts). and its better if ure totally "open" with ur partner, parents etc.

Communication....without it u cant have anything else that a relationship needs or requires

I said trust. Because if you dont trust someone enough you wont have communication. But all the above is grounds for a good relationship.

All of those are important factors and the lack of any of them have the equal capability to destroy a relationship but if you surveyed a group of people most of them would probably tell you out of those choices, lack of communication has effected at least one romantic relationship in their lives. Because the majority of men have difficulty communicating either their feelings or communicating them in a productive manner. Also, if a female feels intimidated to express her feelings or thoughts to a man because he carries himself as if it's "mushy stuff" or "fluff" that he doesn't care to deal with, it will hinder a female from expressing communication that is desperately needed. Most common reason for the stereotype that females want a sensitive man. But not so much so that it demasculates him. From experience, lack of communication played a huge role in my divorce, among other things.

Both communication and trust equally important

Well for me, communication is the most important ingredients to a relationship. It will increase the excitement between the two couple.