the best is very subjective...do you mean favorite? my favorite of the toy group is the tibetan spaniel. herding is gsd and working would be the fila. the best herder is probably the border collie, closely followed by the australian cattle dog, because those are the most highly bred for herding, every instinct they have is geared towards herding so they are probably the best at it.
Sporting Group - Weimaraner
Hound Group - Greyhound
Working Group - Doberman Pinscher
Terrier Group - Airdale Terrier
Toy Group - Can you guess...lol
Non-sporting Group - Standard/Miniature Poodle
Herding Group - Border Collie
I believe miscellaneous group in Canada is what non-sporting group is in the states. Though I may be wrong.
Hound Group - Greyhound
Working Group - Doberman Pinscher
Terrier Group - Airdale Terrier
Toy Group - Can you guess...lol
Non-sporting Group - Standard/Miniature Poodle
Herding Group - Border Collie
I believe miscellaneous group in Canada is what non-sporting group is in the states. Though I may be wrong.
Herding: Take a wild guess. 
Along with BCs, I love Aussies and admire Kelpies.
Hound: I'm generally not a sighthound person, but I ADORE Pharaoh Hounds.
Working: Any of the Mastiffs
Sporting: English Setter
Non-Sporting: Toss-up between the Standard Poodle and the Chow Chow
Terrier: I love all the smaller terriers, Jack Russells in particular.
Toy: Papillon or Cavalier King Charles Spaniel
Along with BCs, I love Aussies and admire Kelpies.Hound: I'm generally not a sighthound person, but I ADORE Pharaoh Hounds.
Working: Any of the Mastiffs
Sporting: English Setter
Non-Sporting: Toss-up between the Standard Poodle and the Chow Chow
Terrier: I love all the smaller terriers, Jack Russells in particular.
Toy: Papillon or Cavalier King Charles Spaniel
Hmmm...here are mine.
Favorite herding dog: German Shephard
Favorite working dog: Doberman
Favorite toy dog: Bichon Frise or Coton du Tulliar (spelling may be wrong)
Favorite sporting dog: Labrador Retreiver or Golden Retreiver
Favorite non sporting dog: Standard poodle
Favorite hound dog: Bloodhounds
Well those are some of my favorite dogs.
Favorite herding dog: German Shephard
Favorite working dog: Doberman
Favorite toy dog: Bichon Frise or Coton du Tulliar (spelling may be wrong)
Favorite sporting dog: Labrador Retreiver or Golden Retreiver
Favorite non sporting dog: Standard poodle
Favorite hound dog: Bloodhounds
Well those are some of my favorite dogs.
Sporting Group - Probably a Lab
Hound Group - Dachshund! And Basset Hounds. And then for the sighthounds, I like: Basenjis, Pharoah Hounds, and Ibizan Hounds.
Working Group - Rotties, Akitas, Malamutes, Mastiffs, and Boxers!
Terrier Group - American Staffordshire Terrier, and the Staffies.
Toy Group - Probably Pugs, but followed up by they Pekingese if they are in the Toy group!
Non-sporting Group - French Bulldog, English Bulldog, Chow Chow, and the Boston Terrier
Herding Group - GSDs and Aussie Cattle Dogs
Miscellaneous - Hmmm....I'd have to say a Thai Ridgeback!! I LOVE these dogs.
Hound Group - Dachshund! And Basset Hounds. And then for the sighthounds, I like: Basenjis, Pharoah Hounds, and Ibizan Hounds.
Working Group - Rotties, Akitas, Malamutes, Mastiffs, and Boxers!
Terrier Group - American Staffordshire Terrier, and the Staffies.
Toy Group - Probably Pugs, but followed up by they Pekingese if they are in the Toy group!
Non-sporting Group - French Bulldog, English Bulldog, Chow Chow, and the Boston Terrier
Herding Group - GSDs and Aussie Cattle Dogs
Miscellaneous - Hmmm....I'd have to say a Thai Ridgeback!! I LOVE these dogs.