Brett certainly gave the most definitive portrayal of Holmes. One must remember that Holmes, although a decent and upright gentleman had his dark side -- his conceit, impatience with people of lesser intelligence and, as a product of imperial Victorian England, he displayed traces of jingoism, racism, sexism and hypocrisy. Note that episode where he remarks on the French surname of a suspect (The Red Headed League) or in the cavalier manner he uses pejoratives to refer to peoples of Asiatic origin. In another episode he tells Watson that his nemesis the Countess of Pernambuco is "but a woman." Expecting high moral standards of others, he was nevertheless a drug addict (cocaine in the original stories by Doyle and also absinthe in the Granada series). He also smoked opium occasionally when in disguise to track down suspects or missing persons. In one episode he was caught red-handed by Watson (the one portrayed by Hardwicke) with a syringe although it is not certain what drug it was supposed to contain, probably morphine as I doubt if heroin had already been extracted from opium at that time. His proclivity to use such drugs make his attachment to pipe tobacco seem trivial.
These flaws viewed in the context of the era and of the peculiar circumstances of Holmes, instead of casting him as an ogre, make him all the more human and believable. On the whole, however, Brett's Holmes is exceedingly kind, self sacrificing and high minded. He could also be quite droll and able to take jokes at his expense as when a phrenologist remarked that he would very much like to take a cast of the cranium of the very intelligent Holmes "until the original should become available" for the latter's collection. Holmes feigned anger and laughingly shooed the scientist away. Note that he rarely collects fees and places life and limb on the line for his clients. No wonder the sophisticatedly discerning French have a Jeremy Brett society.
Between Burke and Hardwicke as Watson, one is likely to vote for Burke as he is funnier, younger and good looking. But Hardwicke better displays the character of a retired officer of the Indian (Imperial British) Army by his physical courage and readiness to use his firearm. His portrayal also highlights the difficult side of Holmes as in the episodes showing Holmes' disregard for his own health and his drug addiction. It was to Hardwicke's Watson that Holmes unusually expresses (in a letter in The Hound of the Baskervilles) deep concern and affection with such words as "there is nothing that I desire more than to have you safely back in our Baker st. lodgings." Finally, if you have seen all the episodes, watch them again and keep your eyes peeled for those delicious antiques -- porcelain washbowls, iron stoves, 19th century lamps, brass door knockers, handsome hansoms and carriages, even a pristine horse drawn red and brass fire engine with immaculate white hoses. And were those mansions, manor houses and country cottages merely sets or genuine locations? I suspect the latter. I would suggest to the English that they revise their Sherlock Holmes tours to include visits to places where Granada shot the series.