I don't have a 'worst bass' but I have several that were terrible out of the box. (40 something years in repair I can get just about anything to play), but fresh from the factory, the worst by far was Epiphone Allen Woody. It arrived with 22 different height frets (every 3rd. note was unplayable), the wrong neck angle (I had to grind down the saddles, and recess the bridge ferrules to get it low enough, the pickups were wired backwards, the list goes on and on. It is finished, and plays beautifully now, but I would pity a beginner, or someone that doesn't have the repair chops I have, who got this bass.