Formal:
* 谢谢 (xièxie): This is the most common and versatile way to say "thank you." It's appropriate in most situations.
* 感谢 (gǎnxiè): This is a more formal way to say "thank you," often used in writing or when addressing someone with high status.
Informal:
* 谢谢 (xièxie): This is also used informally.
* 多谢 (duōxiè): This is a slightly more informal way to say "thank you" and can be used with friends or people you know well.
* 谢谢啦 (xièxie la): This is a very informal way to say "thank you," often used with close friends.
Other expressions of gratitude:
* 非常感谢 (fēicháng gǎnxiè): This means "thank you very much."
* 太感谢了 (tài gǎnxiè le): This means "thank you so much."
* 真是太谢谢了 (zhēnshi tài xièxie le): This means "really thank you so much."
The best way to say "thanks" in Mandarin will depend on the specific situation and your relationship with the person you are speaking to.