Minetta Tavern. It's a place on MacDougal Street near NYU that makes their burger from dry-aged beef, then braises it in butter. It's a $25 burger, but it is unlike anything you've ever tasted in your life.
JAckson Hole makes some fantastic burgers. My fave is the Guacamole burger, which is served with guac, tortilla chips, salsa n sour cream. Who needs the deluxe platter (ie, fries and a pickle) with all of that?! Damn, now I'm all hungry and crap. :S
Ahhhhhhh, Pipers Kilt. I used to love going there. Their burgers were good, but their All You Can Drink Sunday Brunch was the best. The best burger I had was at a bar called McCales or McAles, on 9th ave in the mid 40's, west of the Marriot. We used to call them brontosaurus-burgers because it was the size of the plate. That with a side of steak fries (and some lipator) made for a great lunch. It was also the place that they filmed the bar scenes in the movie Money Train.......
Anyway that bar is gone now and I haven't been to Pipers Kilt in 15 years.