The Kevin Bacon Manifold: Or How There Is Actually Only One Fictional Universe
This works better for some characters than others. Here's a list to get the conversation started, with the added bonus of stringing the characters together in an insane version of six degrees of Kevin Bacon in order to further demonstrate that all television shows and movies are actually occurring in the same fictional universe.
Nathan Fillion. Richard Castle is obviously just the day job for Captain Hammer.
Neil Patrick Harris. Ground into pseudo-sociopathy by the pressures of being a teenaged doctor, Neil Patrick Harris decided to stop being sad and instead be awesome. Doctor Horrible is clearly a persona from Barney's playbook.
Alyson Hannigan. After the final episode of Buffy, Willow kicked that Kennedy idiot to the curb, and went to Wesleyan to finish her college education. It's not a coincidence that flashbacks of young Lily are essentially variations on Evil Willow.
Jennifer Morrison. After leaving Chase, Cameron moves to New York City, immediately marries the Captain, and channels her irritating goodie two shoeism into protecting decrepit buildings instead of genocidal dictators.
Omar Epps. After being unable to take any further abuse from Eriq La Salle, Epps faked his own suicide, and left Chicago to find work as a doctor on "House." This is especially notable because working for a miserably masochistic drug addicted narcissist was preferable to working another day for Eriq La Salle.
George Clooney. I find it absolutely plausible that Doug Ross left County General on "ER", failed in an attempt to become Batman, and then after his career as a bank robber in Out of Sight, was recruited into the CIA in Syriana, and finally went back to his robbery roots to become the con man of the Ocean's 11 franchise.
Julianna Margulies. Carol and Doug only lasted one night before she returned to Chicago, got her law degree, and married Chris Noth.
Originally a detective in New York City, after being fired from the force Chris Noth quickly became extraordinarily wealthy (I assume that he worked at Barney's firm) and attracted the attention of one Carrie Bradshaw. That fell apart off screen and Noth moved to Chicago and met Julianna Margulies. Little known fact: the actual person with whom Noth cheated on Margulies was his one true love, Lenny.
Lenny later partnered with Benjamin Bratt, who after years of going to medical school after hours between murder cases, became a successful fertility expert and moved to Los Angeles.
Bratt worked at the titular "Private Practice" with Taye Diggs, who before becoming a heart surgeon was a secret service agent in the Bartlett White House. He left to become a doctor after being unable to cope with losing Zoe to kidnappers.
After his disastrous run for a congressional seat, Rob Lowe had a mild stroke, leading to various verbal tics like his pronunciation of "literally." Recalling that a certain lovable bear enthusiast was from the great state of Indiana, Lowe moved there to become a government consultant, his dreams of political office forever crushed.
Rashida Jones only went to nursing school after the collapse of the American paper industry and the loss of her branch of Dunder Mifflin.
On "The Office", wonder salesman Timothy Olyphant was actually Raylan Givens on an undercover mission to establish Creed's connection to Boyd Crowder.
And Walton Goggins' Boyd is of course Shane Vendrell, having faked his own death and gotten the hell out of Los Angeles. This of course implies that the massive police presence due to the visit of the President at one point in "The Shield" was in fact Bartlett's visit to Los Angeles in support of Sam Seaborn's congressional campaign.
Also on "The Shield", Jay Karnes' character Dutch joined the ATF after the series, as seen on "Sons of Anarchy".
I could go on, but I think the evidence speaks for itself that all television shows and movies occur in the same fictional (or non-fictional universe). Perhaps most horrifying is that due to the propensity for guest starring as villains, and thanks to the various iterations of "Law and Order", most characters have apparently visited New York City in order to murder someone at one point or another.
As for pieces set in the future or the past, there are two answers. First, actors playing roles in different time periods are clearly playing direct descendants. Second, time travel. "Doctor Who" truly does bind the entire universe together.
Steven Lloyd Wilson is a hopeless romantic and the last scion of Norse warriors and the forbidden elder gods. His novel, ramblings, and assorted fictions coalesce at www.burningviolin.com. You can email him here.