Excel A to Z, 1 to Infinity
To get a list of letters from A to Z, enter this formula in cell A1: =CHAR(64+ROW()), and use the fill handle to pull down 25 rows.
Excel can be used to quickly create a list of numbers beginning at 1 or any other number running to whatever number you choose - (so long as it does not exceed the maximum number of rows - 1,048,576). Put the first number in cell A1, and then highlight the cells below that you want sequential numbers entered in. On the Home ribbon (in Excel 2010), go to Fill . . . Series, and check off the 'Trend' box. Make sure that the Step value is set to one. Click 'OK' and the list of numbers will appear.