When Larry David and Jerry Seinfeld created Seinfeld, they helped usher in the '90s golden age of TV comedy. It became fashionable to say, Were William Shakespeare alive, he would be doing sitcoms. David's latest show, hbo's Curb Your Enthusiasm (Sundays, 10 p.m. E.T.) is as daringly funny as Seinfeld at its best; this year it earned its first Emmy nomination. But it won't usher in a golden age of comedy writing, because it doesn't use scripts. Like a growing number of shows, Curb is funny, fresh--and improvised. If Shakespeare were writing sitcoms today, he would be nervous.
For each...