Formal:
* Maganda ang buhay. (This is the most literal translation.)
* Mabuti ang buhay. (This emphasizes the goodness of life.)
Informal:
* Ang sarap ng buhay! (This emphasizes the enjoyment of life.)
* Masaya ang buhay! (This emphasizes the happiness of life.)
* Okay lang ang buhay! (This conveys a sense of contentment.)
More expressive:
* Ang ganda ng buhay! (This expresses a strong feeling of appreciation for life.)
* Sulit ang buhay! (This emphasizes the feeling that life is worth living.)
The best way to say it depends on the specific context and the level of formality you're aiming for.