Formal and Literal:
* La loyauté avant tout - This is a direct, literal translation and quite formal. It emphasizes the importance of loyalty.
More Idiomatic and Figurative:
* La loyauté prime sur tout - This is a more idiomatic and figurative translation, suggesting that loyalty is the most important thing.
* La fidélité avant tout - This translation uses "fidélité" which translates to faithfulness or loyalty and is more poetic than "loyauté".
The best translation depends on the context and your intended meaning.