Best line (country) of each class

TeriyakiTanker: Unfortunately there really isn't a straight answer to that.  Personally I would say for all around ease of use top to bottom go Russian for heavies, Russian for mediums, American for turreted TDs, Russian or German for non-turreted TDs, British for Arty, and Chinese for Lights.  Just my two cents.  Each line has stinkers and winners.