33x15 The Day of the Doctor [50th anniversary special; 2nd watch]
In 3D! OK, only anaglyph 3D, but amber-blue rather than the old-fashioned red-green -- the depth isn't as striking, but the colours are better rendered; though pure white has a tendency to go wrong. But anyway, that's not the point. The point is, I put it on to try out the 3D a bit, and ended up watching the whole thing. Brilliant episode. The best ever? Well, dunno... but it does deserve to be up there.
Gavin & Stacey
2x06 Episode 6 [2nd watch]
6x21 Black Hearts
[Watch it (again) on Demand 5.]
Person of Interest
2x19 Trojan Horse