When I first got involved with Orbiter, everyone was using Anim8or, as it was freely available. I 'cut my teeth' on it, and it's a pretty decent program. Since then, I've done alot of work in Second Life, and SL has it's own built in modeling tools, albeit, not useful for creating exportable objects in a useful format, and the modeling tools are a bit limited too. I've played around with blender a bit, but it's complex, and has a funky, (but supposedly really good once-u-get-used-to-it) interface. Same with 3DS Max, I haven't worked through the tuts to get proficient at it as of yet. So for the time being, it's anim8tor, UVMapper (free version) and Photoshop CS2 for texturing.