Reason is sick once you get used to it...its like a much better version of FL
I ain't too familiar with Sonar but I know its meant to be good. Logic is one of the dopest programs out there but you need a midi keyboard to get the best results, cubase is good, but i dont think it compares to logic in my opinion. Pro Tools is industry standard atm but the barrier to entry of using that is the sheer cost involved cos to get the best out of it u need to buy hardware and shit. You can buy the LE version of Pro Tools that doesn't require hardware to use but that aint got as much potential innit. Fruity Loops is the easiest one to get to grips with but you need a whole pile of plugins to be getting the best out of it to be honest.