What is the best way to cook chicken fillets?

Google is your friend, there are many ways.

Brine them first. Overnight is best but you can brine your chicken for 4-6 hours in water with some sea salt or kosher salt - I don't recommend iodized table salt.

However you cook, broiling, pan frying, baking in a sauce, the meat will be far less dry and you don't need to add more salt.

As for the best METHOD...there isn't a BEST method. Try them all and I think you will find that they all have their appeal. It depends on what you're in the mood for. Sometimes I like old-fashioned Southern-fried. Sometimes I want barbecued, in the oven or on the grill, sometimes I want baked in cream of mushroom soup, sometimes I want chicken Italian-style....

I like fried chicken