Formal:
* Je suis une œuvre d'art. (This is the most literal translation and is appropriate for formal situations.)
Informal:
* Je suis un chef-d'œuvre. (This translates to "I am a masterpiece" and is a more playful and informal way to say you are a work of art.)
* Je suis une création artistique. (This translates to "I am an artistic creation" and is a good option for a more casual conversation.)
* Je suis un morceau d'art. (This translates to "I am a piece of art" and is a more informal and colloquial way to say it.)
Poetic:
* Je suis l'art incarné. (This translates to "I am art incarnate" and is a more poetic and figurative way to say it.)
The best option will depend on the specific situation and your desired tone.