Perhaps it's the ability to shop after lunch that lures so many power players to Barneys New York's fifth floor. Or that so many ex-New Yorkers crave the smoked fish flown in from the original Barney Greengrass in Manhattan. Either way, the past year has seen the likes of Ryan Murphy, Sony TV president Steve Mosko and Julia Roberts enjoying matzo ball soup, chopped liver sandwiches and smoked fish. Says Tom Huffman, senior vp unscripted programming at WGN America and Tribune Studios, "It's middle ground for West and Eastsiders; they always know your name and, best of all, free self-parking. I hate to valet."