Amateur astronomy, even if I'm no longer doing astrophotography. This is an old photo, I made this in 2010 (it's the Andromeda galaxy, an easy subject).

Basically anything space related.
Playing KSP, watching rocket launches (sadly not live tho), watching the stars and planets in our night sky, watching the ISS fly overhead and also some very-low-level astrophotography, which is hard in a very light-polluted area, but can still produce astonishing results.

The universe is amazing, I love learning about it, seeing it and being a part of a community that is excited about the future of the human civilization.