Prime Burger (51st and Madison)
Burger Joint (57th btwn. 6th and 7th Avenues)
New York Burger Co. (Park and 23rd Street)
Burger Heaven (53rd and Madison)
Have yet to try Shake Shack (Madison Square Park, 23rd and Madison)
From this list, Prime Burger was my favorite because they really know how to make a medium-rare burger. In my opinion, most burger places overcook a medium-rare burger but this place does it right. Check out the photos below. You can either sit at the bar or sit in these chairs that remind me of retro school desks. You have to slide the table top away to sit on the chairs. Service is cool, all the waiters and waitresses look like they've been working there forever (atmosphere is like Katz's Deli, The Pantry, Philippe's). I didn't watch this on Oprah, and I'm not quite sure if this is Sarah Jessica Parker endorsing this restaurant as herself or Carrie Bradshaw from Sex in the City or both, Sarah on Oprah promoting Sex and the City. Anyway, I'm going back. If you go, make sure you take cash because they don't take credit cards.
Same for Burger Joint. This place serves up burgers that taste similar to the infamous In and Out burger chain in California. They're pretty good, but there's always a long line. The milkshakes rock here.
Since the Shake Shack was closed, we decided to go to the New York Burger Co. This place has the best onion rings (I think they use a beer batter instead of bread crumbs). Their onion rings won a lot of awards. I had the Chicago burger, which was a burger dressed with Applewood bacon and Thousand Island. It was good, but like the other burgers except for Prime Burger, medium-rare was a bit overdone. I like there condiment selection: creamy horseradish sauce, honey-mustard, spicy ketchup, New York sauce (which tastes like A1 steak sauce plus molasses), barbecue sauce, and lots of pickles and onions. This place is a little bit pricey, but good.
Burger Heaven... let's just say that wasn't my favorite.