I can't believe no one has mentioned the Juicy Lucy at Matt's Bar on Cedar, it's legendary!
Matt's Bar is a neighborhood landmark, it's won "best burger" just about every year for as long as I can remember. You guys should check it out. But don't take my word for it, google it.
Here is a write up on Matt's Bar:
Dig into a legendary Juicy Lucy burger in a classic dive-bar setting.
Editorial Rating: Recommended
The Scene
From the outside, Matt's looks like no big deal--just another dark, old neighborhood corner bar sporting faded Grain Belt and Bud signs. It doesn't make much of an impression on the inside, either--a long, skinny bar with a row of plain booths and a jukebox featuring the standard mix of classics, rock hits and some local favorites. But for legions of locals, this is their bar. Sports teams, families and old friends wander in day after day for beers and burgers.
The Draw
How good is the Juicy Lucy? Ask the guy who drove his classic car from Detroit to Matt's, ordered one, then turned around and drove back home. Hundreds of people make regular trips down Cedar Avenue to order one of these thick, hand-made burgers stuffed with bubbling, salty cheese and nestled against a heap of hot fries so big it would make a meal on its own. 
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