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Blender and here

Mayas better but not free.
Blender is free but not as good.

Maya has a far better UI than Blender does, but both can do the same thing. I've tried to use Blender, but could never really get into the program, as everything is a keyboard command. I remember seeing someone propose a better UI for blender, but I don't know if anything came of that.

Blender

Blender cause it's free as in freedom and works on GNU/Linux.

I'm a big fan of Mayo. Will eat it on almost anything. ;)

Blender

Maya is more powerful, if you are a student you can obtain a free 3-year license(you cannot sell your works, but the program has every feature like the "normal" edition).
Blender is good too, it is now a good modeling program, almost as competitive as the expensive ones.