Homebrew PCBs

Hi All,
I just joined this group because I am planning to make a homemade
motor controller using the LMD18201 H-Drive.  I am pretty new at
circuit design but I wanted to attempt this project using the
computer. Inevitably, I ran into some problems.  I tried PCB123 and
some other "free" Cad programs on the net but they all have the
handicaps that limited a succesful product.  What is the most popular
software used on this forum for PCB schematic/layout design?  Are
there any plugins for more common CAD programs like Rhino?
Thanks,
Tei