You can call a top defense an immovable object, so in that case a top offense can be classified as an unstoppable force. As the legend Pusha T said in his song title, "Number on the Board", these teams know how to score and know how to score often. These offenses pride themselves on being able to pick apart opposing defenses. These are the top 10 nfl offenses 2014.
http://www.ranker.com/list/top-10-offenses-going-into-2014-season-v1/riley-baines,
Chicago Bears
Dallas Cowboys
Denver Broncos
Detroit Lions
Green Bay Packers
Indianapolis Colts
New England Patriots
Philadelphia Eagles
San Diego Chargers
San Francisco 49ers