The cities are alike in that they're both densely populated cosmopolitan capitals of their respective countries, but they also have their differences.
We rounded up the factors that are important for both inhabitants and visitors to take into consideration and used them to help settle the debate.
As a side note: Even though I currently live in NYC, I'm a native Chicagoan, so I'm an impartial judge in the matter.
COST
Both London and NYC are notorious for their high costs of living. It turns out that London appears to be more expensive for both inhabitants and tourists, though.
The Daily Mail reported that London is the most expensive city in the world for tourists, according to a TripAdvisor study that compared the cost of a meal for two with wine, along with cocktails, two short taxi rides, and a one-night stay in a four-star hotel. London came in first with a total cost of $484, whereas NYC came in third place with a cost of $466.
Last year, the Independent reported that the Economist Intelligence Unit's 2014 Worldwide Cost of Living survey ranked London the 15th most expensive city in the world to live in; NYC on the other hand, was ranked 26th.
New York City wins because it's the less expensive city for both inhabitants and tourists.
HOUSING
Housing is also more expensive in London. According to Global Property Guide, London ranks number two (Monaco is number one) in terms of the world's most expensive cities to rent and buy. It costs $34,531 per square meter to buy in London. It costs $18,499 in New York City. The average monthly rent for a 120 square meter apartment in London is $6,856, according to TransferWise. It's $6,553 in NYC.
New York City wins again because housing is slightly cheaper there than it is in London.
TRANSPORTATION
In New York City there's the subway, and in London there's the tube. According to Time Out, a total of 1.65 billion people ride the subway and a total of 1.2 billion ride the tube. With 24 lines, 468 stations, and 659 miles of track, the subway covers a larger ground than the tube, which has 11 lines, 270 stations, and 249 miles of track. The subway also runs 24 hours a day, while the tube generally stops running at midnight.
Not only does the subway cover more ground than the tube, it's also less expensive to use. A single subway ride costs $2.75, and an unlimited monthly pass costs $116.50. A single ride on the tube costs around $7.30, and a monthly pass for zones 1-3 costs about $191.
New York City wins because the subway is cheaper, covers more ground, and runs later than the tube.
UNEMPLOYMENT RATE
New York City has a slightly higher unemployment rate than London. As of March 2015, the unemployment rate was 6.6% in NYC. London's rate was 5.6% as of February 2015. The number of people in London aged 16 to 64 who had jobs as of February 2015 was 73%, whereas the number of people aged 16 to 64 who had jobs in New York City was 57% as of March 2015.
London wins due to a slightly lower unemployment rate.
RESTAURANTS
A dish from the Chef's Table at Brooklyn Fare, a New York City restaurant with three Michelin stars.
It's hard to find the exact number of restaurants in New York City and London, which makes it difficult to say which city has more. But in terms of quality, NYC seems to be ahead.
One hundred and twenty six of NYC's restaurants have been awarded Michelin stars, just over twice the number of London's Michelin star rated restaurants (62).
There are also nine NYC restaurants that made it onto the World's 100 Best Restaurants list, whereas only five London restaurants made it onto the list.
New York City wins over London since more of its restaurants made it onto prestigious restaurant ranking lists.
NIGHTLIFE
New York is called the city that never sleeps for a good reason: Nightlife in NYC goes on well into the morning, with clubs and bars staying open much later than those in London.
London pubs generally close at 11 pm, and bars stay open till 1 to 3am on the weekends (12:30-1:30am on the weekdays), according to TripAdvisor. Most London clubs remain open till 4am, and a select few keep the party going till 7 or 8am.
NYC bars offer longer hours: the majority of bars in New York stay open till 4am on the weekends. Some stay open this late on weekdays as well, but a number of them close an hour or two earlier. Clubs in New York go on well into the early morning hours.
However, London wins when it comes to numbers. TripAdvisor has a total of 1190 nightlife establishments listed for the city; NYC has only 816.
Although London has more bars, New York City wins since bars and clubs generally stay open later than they do in London.
ATTRACTIONS
Although it's hard to calculate the quality of the attractions in each city, it's easy to see which city has more tourist attractions - and that city is London. According to TripAdvisor, London has a total of 492 sights and attractions, while New York City has 295. London has 38 more museums than NYC (262 vs 224) museums, and 36 more tours and attractions (475 vs 439).
Not only does London have more attractions than NYC, many of London's museums and galleries offer free admission.
NYC does beat London in terms of theaters and concerts, though. The Big Apple has 363, whereas London has 277. That said, both cities are famous for their vibrant theater scenes: London has the West End and New York has Broadway.
London wins because it has more attractions than NYC, and many of them are free.
CONVENIENCES
Convenience refers to how long establishments such as grocery stores stay open and how long public transport operates (ie. if you stayed out partying till 4 am could you still catch a ride home and grab some food at a diner?).
In New York City, it's easy to get just about anything you might want any time of day. Public transportation runs 24 hours a day, and it's easy to find drug stores, grocery stores, and restaurants that are open all day and night. There's also a hardware store, a Best Buy, a gym, and a hair salon that are open 24/7, just to name a few.
Although the tube has plans to launch 24-hour weekend trains come September, as of right now, trains don't run 24 hours a day. And while London does have some restaurants, grocery stores and even clothing stores - there's a 24-hour TopShop - that are open all hours, the selection is much smaller than New York's.
Yelp has a total of 859 24-hour stores listed for London, compared to 5,738 listed for NYC.
New York City wins because its public transportation runs 24 hours and it has more stores that are open 24 hours a day.
POPULATION
As of 2013, London and NYC had comparable populations. London's stood at 8.3 million, while NYC stood at 8.4 million. London, however, has much more room for its inhabitants - it's 138 square miles bigger than NYC. So it's pretty safe to say that New York is way more crowded than London.
London wins because it's less crowded than New York City.
WEATHER
London is often portrayed as a very rainy city. But in reality, New York City gets more precipitation - not just rain, but also snow - during the year. London gets the most rain in October: 2.42 inches is the average. NYC's highest average comes in May and is almost double London's (4.48 inches).
London also experiences more mild temperatures throughout the year. New York City's average lows during the winter months are mostly in the 20s and 30s Fahrenheit, whereas London's winter lows hover around 40 degrees F. NYC's summer highs are around 80 degrees F, and London's are a good 10 degrees cooler, around 70 degrees F.
London wins due to less precipitation and milder temperatures.
GREEN SPACE
According to The Independent, there are a whopping eight million trees in London, and almost half of the city (47%) is taken up by green space. The city's eight royal parks are a good place to start if you're hoping to enjoy some quality outdoor time in London.
New York City, on the other hand, has only 14% green space. The city has over 1,700 parks, playgrounds, and recreational facilities. Some of the most popular parks include Central Park, Brooklyn Bridge Park, Hudson River Park, Flushing Meadows-Corona Park, and the High Line. For a more comprehensive list of NYC's parks, click here.
Considering that London is 607 square miles and NYC is 469 square miles, London definitely has more green space to offer city inhabitants and visitors.
London wins here because it has significantly more green space.
THE WINNER
Considering that New York City won in six out of the 11 categories we used for comparison (London won in five), New York City is the winner of the debate. Although London is less crowded than NYC and offers more green space, better weather, and more attractions than NYC, the 24-hour convenience of NYC, its high quality restaurants, and the fact that it's less expensive gives the city a slight advantage.
Regardless, each city has plenty to offer inhabitants and visitors, making both NYC and London worth a trip.