Just when New York City was hunkering down to weather a real estate slowdown, boom! Hedge-fund billionaire Ken Griffin drops more than $238 million for the penthouse at the Robert A.M. Stern-designed 220 Central Park South, setting a new record. "Painful" is how Compass' Leonard Steinberg describes the two years before the January sale, with brokers struggling to coax buyers into a market flooded by new developments. Now sellers have adjusted pricing to the reality. The median sales tag for luxury homes in 2019's first quarter was $5.85 million, down only 1.3 percent from the same quarter last year, according to a Douglas Elliman report. While there's still a lot of inventory, it's being absorbed at a faster clip compared to 2018. The buyers "were right," says Steinberg. "They waited and now they're buying for less." For the second year, THR highlights the city's top agents who prospered despite sluggish conditions.