There's plenty of them:
Open source Wings3d,box modeler,awsome high and low polygon.
http://www.wings3d.org
Experimental but probably the most promising freeware I've seen is named Aztec(open source also).
http://aztec.sourceforge.net/aztec.php
Free Truespace 3.2 is the best free renderer after the non-linear POV-Ray
http://download.com.com/3000-2186-10187913.html?tag=lst-0-1
The now all-so famous Milkshape3D low poly mdl modeler(supports many formats)
http://www.milkshape3d.com
Gmax is Discreet's free Game-modding product(levels,character) based upon their successful product name 3dsmax
http://www.discreet.com/products/gmax/
Wavefront's free learning edition of Maya an excellent choice just for the knowledge it'll give you.
http://www.aliaswavefront.com/en/products/maya/ple/index.shtml
Softimage Xsi Experience,the successor of the world's unique software who brought you a certain dinosaur movie(Québec product wooho! @_@ )
http://www.softimage.com/products/exp/v3/
Spatch is a Nurbs modeler,looks complicated at first but pretty straight forward in the end,it needs more tools though.
http://www.geocities.com/getspatch/
Anim8or is a very good,stable modeler which is ideal for high polygon modeling but can do lowpolygon efficiently.
http://www.anim8or.com
I have yet to try this ZBrush because people keep saying it's easy and got a good learning curve,I've seen pretty detailed models made in this on cgtalk.com
http://pixologic.com/
Caught by the Fuzz,well I was,still on my buzz
In the back of the Van,with my,head in my hands
