The room isn't handsome, street-slick, or even particularly welcoming. It recalls the kind of establishment that sports a banner running from beam to beam every year proclaiming !oktoberfest! The patrons may have come here straight from their booths at the Javits Center. The staff goes about its nonstop business with cordial if mechanical efficiency, serving onion-and-tomato salads, creamed spinach, and pasty fried potatoes. So why is it always more crowded than Toys 'R' Us on the weekend before Christmas? Because there are few gastronomic sensations that confirm the good life better than a hunk of a spectacular steak. And Peter Luger can broil and deliver one magnificently aged and marbleized two-finger-thick porterhouse after another with the unfailing certainty of Dustin Hoffman adenoidally reciting baseball scores. So don't even ask for a menu. Get big. Eat beef.