New York Magazine has an article on the profitability of various types of businesses in New York.
A Yellow-Cab Driver: Samuel Pekoh
A Four-Star Restaurant: Nobu
A Drug Dealer: 'Nick'
A Private School: Horace Mann School
A Private Investigator: Michael McKeever
A Department Store: Macy's Herald Square
A Diner: Silver Star
A Drug Company: Pfizer
A Soup Kitchen: Yorkville Common Pantry
A Financial Firm: Goldman Sachs
A Yoga Studio: Joschi Body Bodega
A Midtown Building: 666 Fifth Avenue
A Sex Shop: Babeland
A Baseball Team: New York Yankees
A Discount Store: Jack’s 99¢ Stores
A Museum: Museum of Modern Art
A Pizza Place: Nina’s Argentinian Pizzeria
A Clothing Store: H&M Flagship
A Copy Shop: Copyland
A Publishing Company: Random House
City Government: The City of New York
Go read The Profit Calculator.