Blockbench – A low-poly 3D model editor
The main thing that makes this nicer to work in than Blender (for these “pixel art 3D” models) is that you don’t need to UV-unwrap your models. That and the fact that working with “pixel art” painting in Blender is inconvenient at best..I’m actually working on a plug-in for Blender to enable some of this workflow where you can just straight paint on your models :)