Ableton is extraordinarily good - I've seen it do wonderful, wonderful things. A friend of mine once used Max For Live (Max/MSP and Live working together) to write a program that could run an entire theatre using MIDI. Lights, pyro (yes), sound and any computerised contraption that could be plugged in from a single screen. It's a great DAW and a great bit of software.If you want to go with limitless creativity, as in making your own stuff, go with Ableton Live. It's a bit pricey but what you can do in the session view sets it apart from everything - it becomes an instrument at that point.