Boardroom battles and power plays shaped this year's U.S. list, which boasts eight new faces and - surprise! - a new No. 1.
|Yahoo must learn from past merger mistakes|
|Tesla's fight with America's car dealers|
|Amateur investors tap 401(k)s to buy homes|
|Death cross brewing in bond market|
|Yahoo buys Tumblr, promises to not 'screw it up'|