Mine is love, because love is something you can find in the most important things in the world : Family, friendship, relationship, passion ( no matter what kind of passion it is ) . Without love the world something even worst than how it is now.
On this picture you can see my cousin ( on the left ) , he's like a brother to me , and i ( on the right ) , the love between us is the one of the family and i have to admet that this love is one of the strongest i've ever seen.