This Recyclingwatch will leave out the obvious and deliberate references to the series' events since The Runaway Bride.
The Unquiet Dead: Ordinary person lifted to heroism through self-sacrifice.
Aliens of London/World War III: Mal Loup the American newsreader is back, and there's more BBC News 24 hijinx.
Father's Day: Companion causes time paradox which threatens the universe. This is resolved when someone steps in front of a moving vehicle.
School Reunion: Old and new companion action.
The Girl in the Fireplace: Time traveller who makes periodic visits over a long stretch of time to a single individual, though plainly little time has passed for the time traveller.
Rise of the Cybermen/The Age of Steel: Fascist alternate universe.
Love and Monsters: Real life is banal, kids, and you need the Doctor to sort it all out.
Army of Ghosts/Doomsday: People leaping through from alternate universes which are supposed to be closed off.
Human Nature: Somebody getting the chance to experience a life they never had, but this was probably a bad thing.
Utopia: No stars.
Last of the Time Lords/The Sound of Drums: Earth turns into a horrible fascist state, with people crammed in several families to a terraced house, but don't worry, because that timeline's been erased thanks to heroic bravery on the part of the companion. Plus more Doctor-as-Messiah action.
The Sarah Jane Adventures: This story is basically a grown-up version of "Whatever Happened to Sarah Jane," just with the Doctor instead of Sarah.
Good gravy, now they're even recycling *within* the season: Once again Donna has a whole virtual "normal" life, without the Doctor.
Catchphrasewatch: Despite not being in it much, the Doctor gets in a "Brilliant". Otherwise it's left to the companions to make up the quota: Rose contributes a couple of "Brilliant"s, where Donna gets not only a "Brilliant," but a "Don't, just don't," a "No, no, no," and a "I'm tired, I'm so tired."
Old Skool Who: Battlefield *again* (UNIT has a black female leader with an African name, but who is quite clearly British). Faction Paradox (creatures which gain energy from changing the universe), and specifically the BBC Doctor/Faction novel "Alien Bodies" (Doctor's latest companion has too many coincidences surrounding her life). Evil of the Daleks (time travel with mirrors). Planet of the Spiders (woman with invisible insect/arachnid on her back). The American Telemovie (the Doctor is apparently dead).
Everything Else: "It's a Wonderful Life," "Sliding Doors," Marvel Comics' "What if...?" series, "Back to the Future" and pretty much any other "what if such-and-such trivial event happened and changed the universe?" type movie/TV show. "Quantum Leap" (Alt-Donna leaps back to the psychological moment to get history back on track, advised by Rose). "Terminator" (another leap-into-the-past-and-change-history story; Donna lands in Chiswick in a crouch which is a plain homage to the landing scenes in that movie). "La Vita e Bella" (Italian man, on his way to the concentration camps, lying and pretending he's going somewhere fun, so as not to cause people to worry). Philip Pullman's "His Dark Materials" trilogy (there's a darkness out there which threatens all the alternate universes, and a blonde girl leaps from universe to universe in an attempt to stop the entropy). Hellraiser (Chinese fortune teller kick-starts a chain of events which lead to death and destruction). Cloverfield (everyone is running away from the giant spider, but the protagonist runs towards it)