Formal:
* Ninapenda nchi yangu. (This is the most literal translation and is suitable for formal occasions.)
Informal:
* Naitaji nchi yangu. (This conveys a stronger feeling of attachment and love.)
Poetic:
* Nchi yangu, nakupenda. (This is a more poetic and expressive way to say it, meaning "My country, I love you.")
Ultimately, the best way to say it depends on the context and the level of formality you want to use.