Formal:
* J'aime la Louisiane. (I love Louisiana.)
* Je suis amoureux/amoureuse de la Louisiane. (I am in love with Louisiana.)
* La Louisiane me fascine. (Louisiana fascinates me.)
Informal:
* J'adore la Louisiane! (I adore Louisiana!)
* La Louisiane, c'est mon endroit préféré! (Louisiana is my favorite place!)
* J'ai un faible pour la Louisiane. (I have a soft spot for Louisiana.)
You can also use more poetic phrases, such as:
* La Louisiane, un pays enchanté. (Louisiana, an enchanted land.)
* La Louisiane, mon cœur y est attaché. (Louisiana, my heart is attached to it.)
The best way to express your love for Louisiana in French will depend on the context and the level of formality you want to convey.