Hope and optimism:
* Hope
* Optimism
* Cheer
* Confidence
* Faith
* Courage
* Encouragement
* Joy
* Happiness
* Enthusiasm
* Exuberance
* Zeal
Motivation and action:
* Determination
* Resilience
* Perseverance
* Grit
* Willpower
* Motivation
* Drive
* Passion
* Energy
* Action
Contentment and peace:
* Peace
* Tranquility
* Serenity
* Contentment
* Satisfaction
* Fulfillment
* Calm
* Harmony
Other antonyms:
* Joy
* Happiness
* Delight
* Pleasure
* Excitement
* Apathy (in the sense of not caring about the situation)
* Indifference
The best antonym for "despair" will depend on the specific context in which it is used.