Formal:
* Pourquoi m'aimer? (Why love me?) - This is the most direct translation and is formal.
* Pourquoi m'apprécier? (Why appreciate me?) - This is a less intense option, still formal.
Informal:
* Pourquoi tu m'aimes? (Why do you love me?) - This is a more informal way to say it, and is used with someone you know well.
* Pourquoi tu me kiffes? (Why do you like me?) - This is a very informal and slangy way to say it.
Adding more context:
You can also add context to your question to make it more specific. For example:
* Pourquoi tu m'aimes autant? (Why do you love me so much?)
* Pourquoi tu m'aimes comme ça? (Why do you love me like this?)
It's important to choose the right translation based on the situation and who you are talking to.