Formal:
* تشکر (Tashakor) - This is the most common and formal way to say "thanks."
* سپاس (Sepas) - This is another formal way to express gratitude, often used in more serious or official contexts.
Informal:
* ممنون (Mamanun) - This is a more casual and everyday way to say "thanks."
* مرسی (Merci) - This is the most informal and common way to say "thanks," similar to "thanks" in English.
Other variations:
* خیلی ممنون (Kheyli Mamanun) - "Thank you very much"
* از شما ممنونم (Az shoma mamanun) - "Thank you" (literally "I'm thankful to you")
The best way to choose the appropriate expression is to consider the context and your relationship with the person you're speaking to.