When it came to generating profits last year, no U.S. company was better than ExxonMobil Corp. ( XOM ), No. 23 on the latest BusinessWeek 50 list of America's top-performing companies. In 2003, the world's largest oil company racked up record earnings of $21.5 billion, up 91% from 2002, on revenue of $246.7 billion. In addition, the Irving (Tex.) energy giant posted industry-leading return on capital employed of 21% and cash flow from operations and asset sales in excess of $30 billion, while returning a record $11.5 billion to shareholders through dividend payments and share purchases.