That's a hard question to answer. Each is different, and each has different uses. Some would say that things like Absynth are only good for dance music, while the Spectrasonics stuff is more geared towards sound design. I don't look at it that way. They are all just like having different pallets at your fingertips, its all a matter of taste.
I run a reasonably well equipped studio in a special needs school and besides the software mentioned I have access to a range of soft synths, probably about 15 or so different bits of software, and lots of vintage outboard gear I've collected over time. When I'm recording my own tracks, or my students we tend to experiment with 3 or 4 different synths, and just go with what feels right for the song or tune in question - As MK himself says, the song is king. If its not working leave it, come back and try again later. Learn your software inside out, push some buttons, turn some dials, draw some waveforms and see what happens!
With regards to sheet music for specific DS parts, I've not come across anything particularly detailed, but it might be worth considering looking into things like drones (which feature quite a bit).
Ultimately I'd encourage you to develop your own sounds, as a DS/MK fan your influences will come through naturally without trying to copy or force anything - I learnt that the hard way and it took me a long time to stop emulating and start creating.
Sorry for the long reply, I'm very passionate when it comes to music!