Which is a better dog a Lab or a Chesapeake Bay Retriever?

This would be a matter of opinion mostly. A chesapeake is a very strong, dominant dog with a huge drive to retrieve. A lab has similar drive to retrieve, but is not so dominant and protective of its owners. The lab generally doesnt have the muscle tone a chessie does either.
Both breeds are very smart, courageous, and have a willingness to work. They generally all have a bright and happy disposition.