LightWave! I haven't bothered playing around with any other 3D packages lately.
"Stephen Wolfram is the creator of Mathematica and is widely regarded as the most important innovator in scientific and technical computing today." - Stephen Wolfram
you haven't seriously played with any other 3d packages anyways =\
I've used 3DS for quite some time, but my experience with MAYA is very limited. I have never tried SoftImage and Houdini out myself, I've just seen some professional people do so.
"Stephen Wolfram is the creator of Mathematica and is widely regarded as the most important innovator in scientific and technical computing today." - Stephen Wolfram
That is it! I am installing Maya, and going to mess with it. I would have to say to know PS too, that always helps(Dont have to, but it is good to understand Gradients and stuff).