People can argue forever about what is best, but going by sales and popularity alone, it is weird to exclude Sonar while including FL Studio and Reaper which are less common (though well-respected).
I am familiar with Bitwig, but then again, I read all the trade magazines. It is certainly not a contender for most popular.
i think ProTools, Sonar, Logic, Cubase, Ableton, Studio One, and Reason (in whichever order you like) seem to be the major players. I don't know where Digital Performer is these days in terms of use, but maybe it's on the list.
Anyway, these polls are about as valid as the Facebook tests to see which medieval king you are or which planet fits your personality.