A Christmas Carol - I liked it a lot the first time, but upon rewatching I absolutely love it. Christmas-themed or not, it just really works. It's
the Christmas episode of Doctor Who for me, and easily in my top five ever. It's huge fun, sentimental without being overly schamltzy, Moffat gets to use timey-wimey to tell an actual plot rather than a cop-out resolution, it has bittersweet undertones, brilliant acting all-round though special mentio to Michael Gambon, makes use of both time and space elements of the show, is one of the strongest Matt Smith era scripts and performances, looks the part in terms of CG and set design (like something from a Pratchett novel!) and is a loose adaptation of my favourite book.
The Beast Below - the episode this thread was made for. Never has my opinion of an episode changed so much, and I'm not even quite sure why. Maybe because as a viewer I was still finding my feet in the Moffat-era, and I had newfound respect for it upon reflection - hindsight is a wonderful thing, after all! When I first saw this I disliked it very, very much. But rewatching it now and it's one of my absolute favourites! Great fun, memorable setting and characters, and a lot of nice touches along the way. The plot was interesting enough and apart from the odd bit of awkward dialogue ("Did he do the thing?") I found it really, really enjoyable. I still don't know how my opinion of an episode can change so much!
Last Christmas - it doesn't impress me like A Christmas Carol does, but this is a character piece through and through, and I've come to really value those as a commodity since Series 5. I owe a lot of this ones strength to Jenna Coleman who has somehow worked her way up my list of favourite companions and sits firmly in second... she's making Catherine Tate unexpectedly uncomfortable from her top pirch position! I enjoyed the episode as it was, and aside from the Troughton son who got neglected everyone had a distinctive character and voice here. Even Danny Pink didn't annoy me, and that's an achievement! Even Nick Frost didn't ruin Christmas, and given that Hot Fuzz is usually on telly at that time of year... we're bordering on miracle territory here. I lamented and almost stropped when the episode fooled me into thinking Clara was leaving, and then the following scene turned everything around again! It made me realise how much Moffat had made me care for both Doctor and companion again - something I haven't felt since Series 4. I'm heading into Series 9 more enthusiastic than ever!
Doomsday - I always enjoyed Doomsday, but for many years I compared it to
The Parting of the Ways - in my opinion a superior finale episode not just because it features my favourite Doctor and favourite Big Bad, but because I feel it ventured into more interesting territory. At the time, whilst enjoying Doomsday it felt like exactly the same as the previous finale but without the future setting. It was like The Parting of the Ways...with budget cuts. They couldn't afford the expensive space station sets that year, so we'll just CG some Daleks over some London stock footage, despite the fact we've just done two poorly received and consecutive standalone stories also set in contemporary London. In the years since I think I've grown up a bit (in my defence, I was very early teens when Series 1/2 were new) and I think I 'get' Doomsday a bit more. I care about The Doctor/Rose more than I did back then, and am more invested in the characters. I also now find the Cyber-conversion a more scary and horrifying prospect than back then too. I finally 'get' the fuss over that beach scene and empathise more than I did back then when I was still a bit confused as to why Eccleston bowed out in less than two minutes whilst Rose got nearly a full-blown ten. I still prefer The Parting of the Ways, but I prefer it over every finale since as well. Doomsday is just another of my favourites.