Formal:
* J'ai beaucoup de chance. (I have a lot of luck.) - This is the most common and neutral way to say it.
* Je suis très chanceux/chanceuse. (I am very lucky.) - This emphasizes the feeling of being lucky.
Informal:
* J'ai de la chance! (I'm lucky!) - This is a more casual and enthusiastic way to say it.
* Quel chanceux/chanceuse je suis! (What a lucky person I am!) - This is a more expressive way to say it, with a sense of surprise or gratitude.
* Je suis trop chanceux/chanceuse! (I'm too lucky!) - This is a more playful and exaggerated way to say it.
You can also use expressions like:
* J'ai la chance d'avoir... (I'm lucky to have...) - This emphasizes the specific thing you are lucky to have.
* C'est incroyablement chanceux! (It's incredibly lucky!) - This emphasizes the level of luck.
The best way to choose the right phrase depends on the context and the feeling you want to express.