Formal:
* 我爱爸爸 (wǒ ài bàba) - This is the most direct and literal translation, meaning "I love father."
* 我爱您 (wǒ ài nín) - This is a more respectful and formal way to say "I love you," and can be used for your father, especially if you are talking to him directly.
Informal:
* 我爱老爸 (wǒ ài lǎobà) - This is a more casual and affectionate way to say "I love Dad."
* 我爱爹 (wǒ ài diē) - This is a very informal and intimate way to say "I love Dad," and is often used by children to their fathers.
Other options:
* 我爱你 (wǒ ài nǐ) - This simply means "I love you," and can be used for anyone, including your father.
* 爸爸，我爱你 (bàba, wǒ ài nǐ) - This combines the formal "father" with the informal "I love you," making it a good option for expressing affection while still showing respect.
Ultimately, the best way to say "I love Dad" in Chinese is the one that feels most natural and appropriate to you.