Formal:
* தேவாதி தேவன் துதி (Devadhidevan Thuthi): This literally translates to "Praise the God of gods." It's a very formal and respectful way to say it.
* கர்த்தர் துதி (Karthar Thuthi): This translates to "Praise the Lord," using the word "Karthar" which is the Tamil equivalent of "Lord."
Informal:
* கடவுள் துதி (Kadavul Thuthi): This means "Praise God" and is a more casual way to express praise.
Common Expression:
* அல்லேலூயா (Alleluia): This is a Hebrew word that is commonly used in Christian worship and is a very common way to express praise in Tamil.
Ultimately, the best way to say "Praise the Lord" in Tamil depends on the context and your desired level of formality.