2. The Christmas Invasion
The Christmas Invasion triumphantly proved that millions of people across the country would happily watch an episode of a science fiction show on Christmas Day (try telling that to Michael Grade in 1989). The nation followed up the Queen's speech and whatever episode of Only Fools and Horses was on that day with David Tennant's debut outing as the Doctor. Did it live up to the stellar first series that went out earlier that year? You bet. Russell T Davies knew exactly what his task was - prove that Doctor Who can celebrate Christmas and reassure all those new fans that this skinny stranger is the same hero last seen facing down the Daleks a few months before. Each was achieved, and then some. The Christmas Invasion is the logical, culminating celebration of Doctor Who's return - with Rose's personal challenge being to learn to embrace change, and that the Doctor will always be there even when he seems unlikely to return. It's a message that resonates with the show itself and gives The Christmas Invasion a certain gravitas that Davies' future specials lacked. The 10th Doctor is unconscious for most of the episode - a bold move: you'd think Davies would want the new guy to hit the ground running - but his absence pays off by the end, when Tennant arrives late to his own party and promptly steals the show he was largely missing from before. The man is spectacular here, proving beyond doubt that he is the Doctor and stealing the hearts of millions armed with little more than a dressing gown, a satsuma and an unrivalled charisma that rightly made David Tennant the man of the decade. The Doctor's claim to being a "No second chances" kind of man perhaps didn't quite play out (offering to forgive the Master and save Davros from his own catastrophe), but the 10th Doctor exploded onto our screens in an unforgettable way, in an equally unforgettable Christmas Special that set the bar high for all of its successors.