Today, Groupon in New York City is having a special burger day with 13 burger deals across the city. These deals are available until midnight. Participating restaurants are:

• PubOne (Brooklyn Heights): $25 for Two Burgers and Two Draft Beers
• BareBurger (Greenwich Village): $12 for $25 Worth of Organic Burgers and More
• The Mad Donkey (Queens): $10 for $20 of Burgers, Beers, and More
• Corner Burger (Brooklyn): $9 for $18 Worth of Burgers, Poutine, and More
• Lucky's Famous Burgers (two locations): $10 for $20 Worth of Burgers, Fries, Shakes, and More
• Burger Burger (Financial District): $7 for $15 Worth of American Fare and Drinks
• Burger Zone (Upper East Side): $7 for $14 Worth of Gourmet Burgers and Sandwiches
• Dugout Pub & Grill (Staten Island): $7 for Choice of Hamburger, Fries, and a Draft Beer
• Fortago Burger Bar (Upper West Side): $7 for $15 Worth of American Fare
• EJs Luncheonette East (Upper East Side): $6 for Any Deluxe Burger or Kobe Beef Sliders
• Heartland Brewery (Midtown South): $6 for One Burger
• Fresh and Fast (Flatiron): $5 for $10 Worth of Burgers and Drinks
• Mark Burger (East Village): $3 for Two Regular or Bacon Sliders

We haven't been to all these burger joints; got any recs? We like Heartland Brewery (we've only reviewed the Union Square location) and Mark Burger.