This is an age old debate and opinions vary.
In some ways, it's like asking whether you prefer red or white wine and which winery is the best. It just depends...
Here are some of the longer threads on this topic which I hope you find helpful.
German Shepherd Dog Forums - Search Results
Linus van Pelt Haus Juris CGC. My Sweet Babboo, born March 17, 2014.
Madeline Ronan Heart (Maddie) Dec 1997 -- November 22, 2013 Rescue GSD, Sable