In the entire Madden Franchise,
Madden '06 for Xbox 360 is the worst Madden game. This is even considering early Maddens, and I'm making some adjustments for release because obviously the original 1992 Madden Football game has to be held to a standard of the time.
Madden '06 for 360 was truly terrible. They broke everything by trying to make a game that looked similar to their original hype video for Madden '06 with the insane graphics. The pressure was on EA because they bought the NFL license earlier that year, it was a new console, and they had a lot of fan pressure to deliver a stunning game that would impress people. What they delivered is the worst Madden ever, and the game was so bad that it took them about 4 iterations to finally deliver a good playing Madden game again, probably in the form of Madden 2012, which was pretty good finally.
It's really too bad because Madden '06 made like a 'lost decade' for the series practically, where '06 was SO BAD and such a bad step back that it took them half a generation just to get back to where they were gameplay wise with Madden 2005 (Xbox/PS2) and Madden 2006 (Xbox/PS2). They'd finally get back there with about Madden '13 (X360/PS3), and the games have steadily improved year over year since then, with the exception of Madden '25, which was a weird rush job for PS4/X1.
Just watch and listen this horrible shit:
https://www.youtube.com/watch?v=pqpzg8V9qGc
To make it even worse, compare that video to this video, which is Madden 2005 on Xbox, a game that came out a year+ before on older hardware:
https://www.youtube.com/watch?v=45UMBlAaHAU
The Xbox (OG) game from a year earlier plays better, sounds better, IMO looks better, and is more realistic looking/playing game of football, with presentation closer to a television broadcast than what they did with '06. '06 was basically trying to replicate this CG Madden video they made for E3 that year, but nobody at EA stopped to throw the brakes on and say "This video looked great... but... can you actually play game of football that way...?" ANd the answer was obviously no.