Hello friends,
I am trying to do my rf remote controller and I am the one who supports do it yourself.That is why I dont want to use already available remote controllers.What my question is what it the best rf module that I can connect to my megas to use as remote controller. 500-600 meters will be suitable for me at the beginning.
Best Regards 
500-600 meters will be suitable for me at the beginning.
Are you sending 1 byte per week or 100,000,000 bytes per second?\
How many of those bytes just absolutely MUST get through?
How much are you willing to do yourself, and how much should the radios do, to ensure that data gets sent and acknowledged?
How much are you willing to pay?
In other words, just what is your criteria for best?
If you want reliable control just buy an off-the shelf R/C system.
If you want to do it yourself ...
I like the cheap nRF24L01+ modules which work very well. But I have only used the short range versions for controlling model trains. I think you would need the version with the external antenna for the range you need.
I got my nRF24s working with this Tutorial
I suggest you use the TMRh20 version of the RF24 library - it solves some problems from the ManiacBug version
The pair of programs in this link may be useful.
...R
May be GSM or Wifi ?