Since series 2 of Doctor Who, every series has had one episode where the main character is largely absent. In series 2 and 3, this was episode 10. It'll be quite interesting to see how the episodes stack up.
The Doctor Dances
Ah... the sublime Squareness Gun. A sound consistent explanation for the threat and a plausible resolution, in which everybody lives (back before "everybody lives" became a cliche).
The banter in this episode between Jack and the Doctor is excellent, and Steven Moffat is definitely on form. Not the strongest episode 10, but a strong contender.
Love and Monsters
The first Doctor-Light episode, and it shows. Yes, the Doctor and Rose are intermingled through the plot, but it's trying to stand on the basis of a top-class guest cast and a monster designed in a Blue Peter competition, portrayed by Peter Kay. Not the worst story of its season, but not the best.
Here's an example of how to do Doctor-Light correctly, though. Light touch all the way through, taken out of the action by a credible threat, so the guest cast are essentially trying to rescue him. And the creepy weeping angels are introduced here. Doubtless the forerunners of some very quiet playground games. Clever Steven Moffat.
The only story that might challenge Blink on this list. Series 4 had a Doctor-Light story, but this isn't it. This is Companion-Light, with Catherine Tate appearing in one scene at the beginning and one at the end. The bulk of the story is told on one set, with a limited set of charaters and a threat that we never explicitly see, but hear in the voices of the actors and see in their faces. It's a dark tale, although not the darkest Who has ever told. Chilling, and very strong.
Vincent and the Doctor
Vincent Van Gogh vs the Giant Invisible Turkey of Despair. Lots of metaphor in there, but despite some beautiful moments, it's not going to win this round.
Ranking for Episode 10
I'm giving it to Blink. And Midnight. Shared. Different stories, different reasons.
Rankings So Far Series 4 > Series 3 > Series 5 > Series 2 > Series 1
Blink brings Series 3 back in to contention, but it;s very close between series 2, 3 and 5 as we get close to the end of time...