Loius Lunch in New Haven, CT.
Voted #1 in Travel Channel’s Chowdown Countdown, I recognized it because I’ve walked past it about a hundred times on my way to other places in New Haven (most notably, Bar, which is across the street) but I’ve never been there. I’ll be going soon.
*Edit: they were given the #1 spot for inventing the hamburger sandwich, which they cook in vertical broilers.