Here is the Mahamrityunjaya mantra of Lord Shiva which is known as the mantra for getting better health and long life.
"Om Tryambakam Yajamahe
Sugandhim Pushtivardhanam
Urvarukamiva Bandhanan
Mrityor Mukshiya Maamritat"
"Om Tryambakam Yajamahe
Sugandhim Pushtivardhanam
Urvarukamiva Bandhanan
Mrityor Mukshiya Maamritat"