Life is Beautiful, the Grand Prix winner at the 1998 Cannes Film Festival, is much like two films in one. In tone, temperament, and intent, they are vastly different -- one is poignant and powerful, the other is light, airy, and a little silly. The movie is the product of Italian comic sensation Roberto Benigni, who wore three hats for Life is Beautiful: director, co-writer, and star. To date, this is Benigni's most substantive film, and it shows that, although he has forged an international reputation by making people laugh (Il Mostro, Son of the Pink Panther); he is equally capable of ha…