“I thought about Once Upon a Time and Agents of S.H.I.E.L.D. immediately. I could see them doing it since they dropped hints. I've actually thought they might do an Asgard arc for a while.” –svs3
“Personally, I'd like to see a Once Upon a Time and Castle crossover. Honestly, does anyone not want to see Regina Mills and Kate Beckett meet?” –James
"Castle and Scandal when Beckett is running for state senator. I'm not a fan of crossovers because they usually feel forced … but that really would have potential to be interesting." –BK
"I would love to see Castle and Scandal, but not as a traditional crossover. The actress who has played Alexis' mom/Castle's first ex-wife Meredith also plays Abby on Scandal, so it would be tricky, but it would be unique. Within the Castle universe Meredith could be the actress who plays Abby, instead of Darby Stanchfield, on the TV show Scandal. Meredith gets into some type of trouble and Castle and Beckett end up helping her out… and that requires going behind the scenes at Scandal." –Susan
"I would love to see Castle with Agents of S.H.I.E.L.D.! It could be done as one of Castle’s escapist fantasy episodes! If they can time travel to be 1940s gumshoes, they could do this!" –Maryann
“I'm still holding out hope that Peter Lenkov's tease comes true and it’s Hawaii Five-0 and Blue Bloods. I'm dying to see Tom Selleck in Hawaii again! The Mustache must return to the islands!” –promogirl2
“How about Heroes Reborn and Grimm? With the talk of wildly different DNA and "The Powers That Be"… I could totally see Hiro doing a time jump with a couple compatriots but something goes wrong and they shift dimensions into the Grimm world. I can even see the end of the Heroes episode when Hiro is asked ‘When are we?’ and he would look around saying, ‘Not when, but where?"” –V
“SVU and The Mysteries of Laura. Mariska [Hargitay] and Debra [Messing] are already friends and both shows could use the ratings boost. That's my guess.” –Sean
“Suits‘ Louis Litt goes to the Hamptons to chase down a signature for a document and gets treated by the country's No. 1 concierge doctor, and then Royal Pains‘ Evan tries to get Hank to sue his former hospital for wrongful termination.” –lrdslvrhnd
BZZT! Sorry, but both these shows will be on hiatus come fall.
"Nashville certainly could use the ratings burst. Maybe a Grey's Anatomy surgeon will work on Deacon?" –Liza
"All I want is for this to be Scandal and Agents of S.H.I.E.L.D., even though I know that it is not. But honestly, Coulson needs some PR help." –Michael
“Scandal and How to Get Away With Murder could work very well! But Viola Davis and Kerry Washington need to be against each other rather than working together!” –Luis
"Empire and Gotham. Cookie heads to Gotham to find out what happened to her long-lost cousin, Fish Mooney, who has gone missing. Jamal and Hakeem perform at the Penguin’s club." –ToyCannon
"NCIS and Criminal Minds! Penelope and Abby together. Poor McGee!" –Debbie
"I'd watch the hell out of Criminal Minds/Scorpion! I can imagine a hacker-off between Penelope and Ralph, interactions between Cabe/Hotch, Paige/JJ discovering things in common, Toby being like a kid at Disneyland with the BAU, Reid/Walter trying to get into each other's brain, Reid/Ralph sharing cute moments, Happy and Morgan getting along well (then awkwardness – and hilarity – ensues as Toby and Garcia side-eye them), Sylvester and Garcia being weirdos together…. Oh, the possibilities!" –Olivia
"I just saw this [WGN America] commercial the other day, so I immediately thought of Elementary and Person of Interest. Elementary always does somewhat fantastical sounding plots based in realism, so I don't think Sherlock would find the idea of a machine that can predict crime too crazy. And as you can see in the commercial, the leads have great chemistry together." –Devin Hudson
BZZT!Sorry, Devin, but Person of Interest is not a fall show this season.
“Sleepy Hollow and The X-Files. People keep comparing Abbie & Ichabod to Mulder & Scully. And all the odd stuff that happens in Sleepy Hollow would definitely attract Mulder. C'mon Fox, make it happen!!!” –EvaBaby
BZZT!Sorry, Eva, X-Files is not a fall show.
“I'd say Empire and Sleepy Hollow because Sleepy Hollow needs a boost and that is wildly different DNA. I doubt Empire would get any more buzz than it usually gets to make it worth it, though I'd love to see what Cookie would have to say about Ichabod Crane.” –westwingwolf
“Bones/Sleepy Hollow. Both shows are on Thursday night, both could use some buzz, and while the shows are completely different, there's enough similar to make it work.” –madbengalsfan85
“Has anyone guessed Bones/Empire? Because I can see how those would work together, and David Boreanaz trying to sing is always a treat.” –NotBri
"Imagine Arrow‘s Oliver teaching Supergirl‘s Kara tough love — like he did with Barry — by shooting her with a kryptonite arrow." –Dean
BZZT!Sorry, Dean, but the Blind Item shows air on the same network.
“I'm calling it now: Supernatural and Arrow. We already know Arrow loves doing crossovers and Supernatural loves doing less-than-serious episodes. All the actors are best buds; in fact I remember reading somewhere that either Stephen Amell or Jared Padalecki had pitched the idea of a crossover to producers. Boom. Evidence.” –Kim
“The Originals and Reign — there are logical reasons for characters to be in the same time period. Or Vampire Diaries and Reign.” –queerbec
"OMG! Bones is going to have an affair with Castle!" –Judy
BZZT! Sorry, Judy, the shows must be on same network. (Internet, you thus may cease catching fire.)