Formal:
* Mi amor: This is the most common and respectful way to say "my love" or "my darling." It's suitable for a partner or someone you're seriously dating.
Informal:
* Cariño: This translates to "dear" or "sweetheart" and is more informal than "mi amor." It's appropriate for someone you're close to, like a boyfriend or girlfriend.
* Amor: This is simply "love" and can be used in a similar way to "Cariño."
* Mi vida: This means "my life" and is very affectionate.
* Corazón: This translates to "heart" and is a very intimate term of endearment.
* Bebé: This literally means "baby" and can be used playfully or romantically.
Other options:
* Mi cielo: "My heaven"
* Mi sol: "My sun"
* Mi reina/mi rey: "My queen/my king"
It's important to consider the relationship you have with the person you're addressing. Using a term like "bebé" for a new acquaintance might be perceived as inappropriate.
Remember that using pet names can be very personal and cultural differences can play a role. It's always a good idea to be mindful of the context and use terms that feel comfortable and respectful for both you and the other person.