Cowboys.
Cowboys Stadium is bigger. The Roman colosseum could hold about 50 000 spectators, while Cowboys Stadium can hold over 100 000 spectators. See all the features of the Stadium at stadium.dallascowboys.com
well actually the Aztec stadium can max out to a total of 120,000 spectors
Build It Bigger - 2006 Dallas Cowboys Stadium 2-1 was released on: USA: 20 April 2009
The London Olympic stadium can hold a legal number of 80,000 people. The Cowboys stadium has room for 80,000 seats, but can be converted to hold 31,000 more standing people.
It has caused a craze for increasingly-bigger videoboards.
obviously the cowboy's because theirs cost over a billion dollars
Wembley
The Cubs stadium, Wrigley Field is about 1,000 seats bigger than the White Sox stadium, U.S. Cellular Field.
Wembley
It is the Azteca stadium with a capacity of 120,000.
The Emirates Stadium, home of Arsenal Football Club, is not the 2nd largest stadium in the world. There are many stadiums in the world much bigger than it and there are stadiums in England that are bigger than it.