Everyone I've ever met considers happiness to be desirable. There is a whole wing of psychology called "positive psychology" studying things like happiness. One of luminaries of this field is Dr. Martin Seligman, who wrote both Learned Optimism and Authentic Happiness. His group publishes a newsletter called Authentic Happiness Coaching Newsletter.
The most recent issue of this newsletter discusses a Model of Happiness developed by Dr. Sonja Lyubomirsky and others. This model describes our happiness as coming from three components.
Our Set Point (50%). This is our natural happiness state. We all know people who seem to always be happy, and others who seldom laugh or seem joyful.
Circumstances (10%) Our life circumstances also influence our happiness. Things like winning lottery or spraining our ankle both influence our happiness, but typically over a short time period. Humans are very adaptable and so major boosts or dips in our happiness are generally short lived.
Intentional Activity (40%). For this description, let me quote from newsletter. "The term intentional activities refers to those thoughts and behaviors that require effort. This effort may be apparent only to us (for example, making a list of goals for week) or it may be visible to others (for example, doing a favor for a friend). They suggest that intentional activities are key to making lasting changes in happiness because such activities are more resistant to adaptation (the process by which we get used to something and become unaffected by it). We can deliberately engage in activities that make us happy while varying them enough to ward off adaptation."