The only formats I wouldn't use are those that are directly evaled as this will have important security concerns or those that put the data into modules, again for security reasons.
A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey JamesMy blog: Imperial Deltronics