If I had to give you a "general" answer, then I guess Ableton Live fits all possible workflows (VSTs, sampling, MIDI, audio "mangling", arranging) the best. FL Studio seems to me like the one which is the fastest as far as pattern based producing goes (even though Ableton Live feels as good, depending on your workflow).
The good thing is, that you can become a "master" at any given DAW or sequencer, so someone with Ableton Live and mediocre knowledge of the program will be always beaten by someone who knows Reason "by heart" and he will be beaten by someone who knows Pro Tools better than he knows Reason, etc...
But as far as different workflows and combination of different soundsources goes, I would have to go with Ableton Live. As far as "Digital Audio Workhorse" goes, I would have to go with Reaper, but that's because I come from the Pro Tools/Logic world originally, so I am used to that kinda approach.