And now, the most expensive co-op sale ever recorded, which hit record books this year. In August, after a fierce bidding war, billionaire and Millennium hedge fund guru Israel "Izzy" Englander emerged victorious and officially paid a whopping $71,277,500 for a palatial duplex at the world's richest apartment building. The 18-room apartment at 740 Park Avenue was formerly occupied by France's ambassador to the UN, which hit the market in April asking a "mere" $48 million. The in-debt nation paid something like $600,000 for the place back in 1979. And now Englander, who already lives in the building, has a "pied-a-terre" for when his children and grandkids come to town. The most priciest win-win ever?

Egypt's richest man held the record for purchasing the city's most expensive co-op—the year's second most expensive sale—for about three months. After a bidding war, construction magnate (and billionaire, of course) Nassef Sawiris spent $70 million on a penthouse at 960 Fifth Avenue formerly owned by the late Edgar Bronfman, Sr. Bronfman passed away in December of last year, and his full-floor, 16-room apartment officially listed for $65M in March. Sawiris will enjoy five bedrooms, 8.5 bathrooms, a ginormous wraparound terrace with 100-feet of frontage along Central Park, and four staff rooms on the floor below. He'll probably need that built-in safe, too. The purchase unseated a $54 million buy further south on Fifth Avenue back in 2012. Small change, these days. Then it was unseated itself by Englander's buy, above. Whew.

Despite reports that 57th Street megatower One57 is having trouble finding buyers for its remaining units on lower floors, high-up apartments that sold last year and closed this year take up three of the highest spots on this list. On the 82nd floor, this apartment sold to Ridgewood 57 Inc. for an eye-popping 56,079,298.25.

One floor down at unit 80, though, the buyer is hidden behind a company called Lapusny. It cost $52,952,500 and closed in November.

Former Coach creative director Reed Krakoff made bank selling a completely lovely Upper East Side townhouse that he and his wife renovated. Among its attributes: a snakeskin bathroom with a "a spheroid toilet more stunning than anything the vast majority of the population will ever own"; a staircase that is reminiscent of the Guggenheim's ramps; and much, much more.

Art Deco condo conversion Walker Tower made headlines this year when Penthouse 1 sold for nearly $51 million, setting a downtown record. It was apparently an all-cash transaction, with the buyer in the full-floor, 6,000-square-foot space for "less than five minutes" before stating "I'll take it." Although public record shows the purchaser is shielded behind an anonymous LLC, rumor has it that it's Neil Moffitt, British-born entrepreneur and CEO of global restaurant/nightclub brand Hakkasan.

Once-troubled tower One Madison now counts celebrities like Gisele Bundchen and Tom Brady along its owners. Add to that magnate Rupert Murdoch, who bought the bonkers triplex penthouse in August; the deal closed in March. The 6,850-square-foot sponsor unit, a 5BR/5.5BA with a wraparound terrace and statement staircase, ultimately raked in $43 million.

One of the most impressive listings of 2013—the design award-winning Central Park West penthouse triplex belonging to billionaire activist, philanthropist, and monkey-saver Jon Stryker—sold in April to a trust for $6M under ask. It's gorgeous.

In May, the penthouse at 1136 Fifth Avenue hit the market asking $30 million. Owned by Warner Music Group CEO Stephen F. Cooper, the tony building is used in establishing shots for Gossip Girl character Blair Waldorf's fictional penthouse home. It was in contract by August. Finance guy Anton Levy picked up the apartment for $5M over ask in September. (Cooper had paid $20M for it, so he came out of the whole thing pretty well.)

In October, the man who invented "American Idol" and also the Spice Girls, sold off adjacent three Plaza apartments—units 901, 902, and 903—worth $38 million. Yes, that would be Simon Fuller. Unfortunately, there are no images of the apartments; only a floorplan for unit 901. Combined 901-903 sold for $33.2M, the sum that made this list, while separated 902 also got plucked up for $4.8M. For the anonymous seller, we imagine another combo is in the cards.