How to be The Spot without getting annoying about it: Be invitingly spacious and open, with high ceilings and bright, Deco-era metal wall paneling. Provide deep-cushioned booths and serve simple, hearty dishes. Employ a wait staff that actually tends to its patrons. Set up an illuminated glass bar that smacks at once of a Blade Runner future and an Ocean’s Eleven past. Hire bartenders who understand that stinginess is always in bad taste. This is basically what Jim Heckler has accomplished with The Globe (373 Park Avenue South, at 27th Street; 545-8800). By day, it feels like a huge thirties diner with better food – the Reuben comes with manchego cheese on black bread, and the kitchen offers a yellowfin burger. At night, the room is notably swankified, as the lights are dimmed, the candles lit, and the dinner and a-cocktail-or-four-after-dinner folks stream in. Yet there isn’t that feeling of crowded, anxious, deliriously furious business-card-sniffing – even with a full house.