I've been using Blitz 3D since I started. It's actually pretty good, but it's no longer supported and it's showing its age. I definitely want to use something new for my next project, something with similar features (3D graphics / code is all text rather than an editor / light on RAM) so I'm checking this thread to look for recommendations. (If you've got a good one, just reply to me directly)
(I've tried unity but found it too fiddly. Same goes for Unreal, and I'm trying to get to grips with monogame but I'm having lots of compatibility issues with models.)
As for everything else, I use milkshape for modelling (this is also really old, and I wouldn't recommend it per se, but it is surprisingly easy/fast to use for simple low poly models, so that's something), audacity and a korg M1 for music/sound.