* חיים טובים (chayim tovim): This literally translates to "good life" or "a good life." It's a common and straightforward way to express the sentiment, particularly in a more general or formal setting.
* לחיים טובים (lechayim tovim): This adds "to" (לְ) making it "to a good life!" It's often used as a toast, similar to "cheers" or "to your health" but with a broader wish for well-being.
* תהיה לך חיים טובים (tehiyeh lecha chayim tovim): This is a more formal and grammatically complete sentence, translating roughly to "may you have a good life." It's suitable for a blessing or a farewell. (The masculine form; for a female, use תהיה לך (tehiyeh lach)
The best option depends on the situation. For a casual farewell, "חיים טובים" (chayim tovim) is perfectly acceptable. For a more formal blessing or toast, "לחיים טובים" (lechayim tovim) or "תהיה לך חיים טובים" (tehiyeh lecha chayim tovim) would be more appropriate.