i started on FL, still use it from time to time. great program but takes a bit of work to do some of the more advanced stuff. the basic sequencer on this is the best thing about it that most other programs don't even come close to matching. so you can make beats on here from scratch then use it as a plugin on another DAW. best advice with FL, is use your own drum kits and 3rd party instruments and effects. i don't recommend using the basic plugins on it (unless you spend extra cash and get the mac daddy super pimped out version of it)
used reason for fun but never really got anything done on it, and didn't really care to since i like to use vsts, yea i know it has refills etc but i like stuff that i can use on multiple programs. yea it has some great tools built in and can be rewired to work with other daws too.
messed around with ableton but it felt awkward so i ditched it.
now i just began working with cubase and i absolutely love it so far. gonna take me a bit of getting used to, but i love everything i've seen so far. fav part so far is the mixer and channel effects stuff you can do with it.
if you work with live bands, vocalists, rappers, or any other "recording" artists, they usually ask if you use ProTools. not my fav for production, but definitely top notch for actual recording. you can always export recorded material and work on it on other programs.
short story: start with Fruity Loops and get some VST pluggins and sample packs and you'd be good to go with a great and easy to use starter kit.
^^all my biased opinion from past experiences^^