Been reading about Pete's Waterfront, Bacchus and Skinflint's, Bonnie's, etc. I've only been to a few of these so I can't make a fully substantiated claim - and I'm sure all of these places make good burgers (and of course, there's room for more than one "best" burger in the world) - but even so I think Sparky's in Williamsburg deserves serious consideration.
Some of you may want to reject Sparky's because it is both in, and of, the self-consciously hip part of Williamsburg. Others may look down at Sparky's precisely because the owner has been so meticulous in his attempt to create a perfect burger-and-hot-dog shack (all Niman Ranch and organic ingredients, specially baked buns, etc.). But given a fair chance I think anyone who truly cares about hamburgers, as I do, would have to admit that these are near-perfect.
Sparky's burgers aren't big wads of meat like some famous NY contenders (e.g. McHale's and Corner Bistro, both of which I enjoy). These are good-sized but fit within the bun. The meat earns its fancy organic pedigree by being notably flavorful and juicy, the special buns are tasty and nicely chewy but not showy or obtrusive (I hate it when restaurants with pretensions of originality ruin good burgers with giant, aggressive buns made of foccacia and other non-burger breads), the bacon (also Niman), and other toppings are all excellent. The total effect is not original, it's more like the perfect realization of the thing you're imagining when you feel like you want a hamburger.
Actually, I think everything on the menu at Sparky's is pretty damn good. Fries are crispy and, though I'm not a seasoned-salt fan, very tasty. Shakes are great. And their various specialty hot dogs are terrific. Not to mention the fact that, at around $7 for a burger with fries, Sparky's is cheaper than many of the NY burger champs.
I'd give it a try if I were you (it's at 135A North 5th Street (Williamsburg/Greenpoint) Between Berry and Bedford Aves.)