Wedl's - Jefferson, WI
Since 1917, these guys have been frying burgers with a little lard and a lot of grilled onions on a flattop in an 8x8 shack on the sidewalk, open summers only. This is seriously one of the tastier burgers I have had in the past couple years. It's a hike, halfway between Madison and Milwaukee on US 18. Balls of fresh ground beef smashed on the griddle, bakery soft buns, you add condiments on your own.