(Spoilers ahead. Though, you probably already know what happens, as you'd have to live under a rock not to know at this point.)
It seems like fans of Lost are having one of two reactions to the finale - either they loved it (and cried!) or they thought it was a cop-out.
I'm of the camp that cried. In fact, I not only cried, but I bawled like a baby, and that's saying a lot since I usually have nerves of steel and I never cry at movies. Ever.
What really got me at the end was the peace and happiness on Jack's face as he (and his friends) were enveloped in the white light. And the peace on his face as he finally laid down to die, knowing that he had done something good and meaningful in saving the island.