I have a lot of different instruments, both hardware and software, for making music, but here is what I use the most at the moment:
I have an actual electric piano but I don’t use the onboard sound engine, preferring to use it as a midi controller for a software piano sound. Recently I bought Ableton Live Full Suite, before I was using the ‘Grand Piano’ sound from the default install. Now there is a whole ‘Piano’ Ableton Live pack, and that seems to offer much more realistic piano sounds.
Lately I’ve been using the Sonic Charge’s Microtonic for drums, because I have been making more dance-orientated music. I find the drums really good, and they’re already fully processed with effects so you can just slot them into the mix. I also have been using the built-in Ableton 909 kit sound a lot, but might move away from that as I don’t like the sound compared to Microtonic. At some point in the future I will probably get my Nord Drum hardware drum synth out, but for now I can’t find the power supply so it’s not working.
I have been using my modular and semi-modular synthesizer as a main bassline synth, with some sounds from Ableton over the top. I have used the Access Virus synth quite a bit for synth duty, and it has some great presets for evolving arps.