In order to delay doing RL stuff, I have been snooping through tag lists on various comms, looking mostly at crossovers and the boys having freaky powers. Here are a few I've saved to my delicious list. Be warned: my love of long fics comes through again. Most of these are at least 15,000 words long, if not more.
Supply and Demand by tari_roo
A generation ago, Kinetics and Empaths were discovered (or rather, created). Alone they can't do much, together they are unstoppable. Unfortunately, there are many more Kinetics than Empaths. There are even fewer unbonded ones. Dean is one of those. Caught and sentenced as an unregistered empath, Dean's in the hands of the government agency that controls access to free empaths, but it may not be what it seems.
There are currently 3 stories in this verse: Unwanted is an SPN/NCIS crossover, where Dean is loaned to Gibbs and they end up working together on a couple murders. Repeat Business is SPN/Criminal Minds. Dean was brought in by the BAU because a murder they'investigated matched the murder Dean had encountered with Gibbs. Then another one happens, even though the murderer is dead. The last story, Stolen, happens in the SGA verse. Dean is kidnapped by Kinetics who need the boost in power an empath gives in order to open a vault on another world.
The author says in the comments that she is, or is planning, on writing more in this verse. Bringing Sam into it, and the angels, but even with the 'I want more' at the end, these are still three wonderfully written and interwoven stories. The link takes you to the author's master list. You have to scroll down to the crossover section to find it. It's worth it!
Angels in the Architecture by rivkat
Mal really needs to stop rescuing siblings. It always brings nothing but trouble. Alright, so this time the Winchesters rescued him first, and it seemed only reasonable to let them come along on his ship for a spell. When the third guy shows up, looking like someone from the central worlds (by way of a ditch), he knows his first instinct had been correct. Too bad it's too late to throw them back.
Rivkat perfectly captures the voices, the characters, and the atmosphere of the Firefly universe. Her Mal, in particular, is so very true to show. (I want my Firefly back! *sigh*). Castiel is hiding Sam and Dean in the future. However, nobody can completely escape their pasts. This is another one that's been left open-ended. I need to go search the author's AO3 account to see if she's added to it.
How to Survive by spectral-scribe
Something is making Dean sick. In desperation, Sam takes him to a hospital. That it just happens to be House's hospital and House has been sent to the clinic to be punished could be good news or bad. House may be the greatest diagnostician in the US but even he's never seen anything like this.
House has once again been assigned to the clinic for failing to be [nice/tactful/discreet/human], when Sam brings Dean in. The snarky banter between them is spot on and priceless. And who can resist a touch of h/c?
Cabin Fever by strangeness&charm
Dean is hurt during a fight with a Hydra and Cas transports him to safety. Unfortunately, the spot he picks is in the middle of having a blizzard. Good thing Mounties are always prepared.
If you haven’t seen Due South, this will make as much sense to you as it does to Dean. Suffice it to say that Benton Frasier puts Dudley Do-Right, Boy Scouts, and Man v Wild, all to shame. There needs to be more Due South fic.
Syndicated Sci-Fi Show by claudiapriscus
Sam and Dean have been lurching from show to show for days. They've been injured, humiliated, screwed with, and forced to live really bad writing. When they're finally plunked down in something a little calmer, if a little odd, they dare to hope they're being allowed a breather episode. After all, it seems to be a show about an expedition poking around some completely non-ominous ruins – like a fantasy version of a history channel special. The boys are sure it's bound to be nice and boring.
Based on the episode “Changing Channels,” Sam and Dean think this is one of Gabriel’s ‘worlds’ It’s not, but they don’t know that, so their reactions to all these life-or-death, end-of-the-world situations is very, very off (and very, very, funny).
Unfortunately, this section has mostly powered!Dean because I tried to pick stories where they didn't have powers that they already had in show, and in show, Sam already has freaky powers. If a story had him able to download knowledge from other people, like a biological intersect or matrix, then I would've included it. Alas, I have no such fic in my memory bank. =[
In Arcadia Ego by glasslogic
Sam is hunting on his own. While stalking vampires in the central states, he is forced to strike a deal with one to save the lives of hostages. Now, torn between a hunting community that’s shut him out and a vampire that enjoys inflicting pain, his father missing, and innocent lives over his head, Sam finds that simple survival might be more than he can manage, and there are even darker things looming on the horizon…
Yeah, Dean’s a vampire, and he kinda-sorta blackmailed Sam into donating blood every once in a while, but what started out as a matyr's duty to save lives becomes a desperate scramble to save his own life as Sam is targeted for death by hunters he thought he knew. Glasslogic is one of my favourite authors. She takes the spn world and gives it a dark twist. I’ll also re-recommend Fortress and its sequel Static, for those who like their Sam/Dean with a dark edge.
Bad Moon Rising by laru_tan_repus
In Burbank, Oklahoma, Dean vanishes in the dead of night, and Sam's attempts to find him yield only a nest of demons. The next day, Sam finds Dean at the hospital, alive and well, if oddly distant. Whatever's up with Dean will have to wait, though; something in the hospital is nastily killing patients one by one, and that's nothing to Yellow-Eyed Demon's budding plans for Sam.
This is a creepy-case fic that’s wrapped up in a canon-based AU, with a twist of angsty wincest. It was the atmosphere in this one that caught me. Dean, the town, everything, seems to be just one step offe. Not… wrong, but not right either. As this was a big bang, there’s lovely art to go with it.
The Apotheosis of Wile E. Coyote by nwhepcat
Even with the clock ticking toward death and hell, Dean insists on taking on a routine job. It's anything but routine when he finds something he's not meant to discover, and things get a great deal more complicated.
Shortly after Mystery Spot, Dean talks Sam into investigating a case in a certain Kentucky town that just happens to have an full-grown oak that grew out of a meteor that fell twenty years ago. Dean, of course, touches it. Oh, and something’s making the townspeople go crazy, crazy enough to kill themselves or someone else. A tight case-fic with h/c, the link is to the author’s tagged memory list since this was written for and in as a comment fic.
We Are Legend by albeitslowly and chocca2
Lucifer grabbed Dean at the convent instead of Sam. Sam wanted him back and figured out how to do it. Now he's the Anti-Christ with the powers of the Four Horsemen and Lucifer is defeated which means Dean's back in his own body but he's kind of not, but Sam's got some ideas on how to fix him. And what Sammy wants, Sammy gets. Except Dean, still bearing the physical "scars" from his interlude with Lucifer, has plans of his own, and he won't back down, no matter what Sam throws at him. What he does, what they do to find each other crosses the line from creepy into downright macabre, but when have Winchesters ever done anything half-assed?
This is a tight, twisted, curtain-fic, where the curtains are tattered and torn and the picket fence is stained with blood. It was painful to read, but I couldn’t stop.
I know there are tonnes more good stories out there and I’d love it if you shared your favourites.