you need to see the moneyword chart in this thread: http://forums.digitalpoint.com/showthread.php?t=2394478 to understand what is the best keyword for you to your success, Ayman X.
What do u mean by maximum Competition for a Keyword. It really depends up on the Keyword you choose and the market. If you have chosen best keyword for your business, it may have more competition and it will take more time to optimize your keyword with search engines. And you cant tell , the competition will stay same all the time. It may increase or decrease in the future. Always competition will be increased at most of the time.