Just curious. I saw a slightly similar thread, but it was more focused on melody than just a musical piece in general (and not everybody writes melodious music, ya know?)
I'll start. Being a chiptuner with out a working Gameboy or cart (or any other chipmusic-dedicated hardware), composing music using LSDJ in BGB with cheap speakers inspires me. I think I get a feeling of satisfaction knowing that the sounds coming out of BGB are as close as an emulator can get to the real thing, so it makes me feel confident that what I'm creating sounds good.
VBA not so much. Although it still gets the job done, I don't feel as inspired when using that emulator.
Another thing that inspires me is when my little sister says "It doesn't bother me. I like this song." when I apologize to her for making her have to listen to my tunes over and over while I'm tweaking/jamming.