A blanket statement to cover from the start - just because a character was mentioned on the prompt, doesn't mean you only have to write about them - or write about them at all, bar a mention to check the rules off!
Well, it's a classic, if seemingly little-known fandom. I have a weak spot for it, though - before SPN, before Lucifer, there was a short-lived TV show that featured a sassy, wise-cracking demon/devil with both a strict side and a fondness for his human counterpart, and a human who had to put up with the aforementioned devil appearing out of nowhere but definitely inside his personal space bubble (and sometimes in his bed, even!)
I love the dynamic between the two of them - the way Ezekiel has no choice but to obey, the way he desperately wants to get back to the wife he left behind, and the way he occasionally looks amused at certain one-liners the devil shoots him. The way the devil regards Ezekiel as a truly good person (imho) who would be either alive or in heaven by now, but for that one pesky little detail of murdering his wife's rapist, the sheer delight he takes in the utter weirdness of humanity.
The fact that there were so few episodes, yet so many more adventures to be had...
The Coldfire Trilogy
I honestly don't even know - it's such a rich and varied world that I honestly think you could do anything with these two and I'd be happy!
That said, adventures post-canon with Damien and Gerald are my weakness - the idea that here is the one person left who truly understands what the other has gone through (or as near as) is a definite plus!
Dead Like Me
Ah, another fandom from long ago and far away! To be honest, I was surprised (but delighted) when it came up on the nominations this year.
As mentioned on the prompt, a roadtrip scenario with the whole gang would be hilarious - where are they going? Is it a works-exchange programme? Who are they going to reap? Who drives, who sleeps in the back all day only to wake up when a song they love comes on, who simultaneously navigates and mediates the squabbles behind them? Who moons passing truck drivers? (Mason, it's always Mason.)
Also as mentioned, I am partial to a bit of Rube/Mason (one seems to have an almost pathological need to take care of people, the other is... Well, the other is Mason) but I understand this isn't going to be everyone's cup of tea, so no pressure!
The Man in the Iron Mask (1998)
... don't judge, oh writer mine, but I have a massive weakness for Athos/Philippe. Yes, there's a massive age difference. Yes, Philippe is the son of one of Athos' oldest friends. Yes, you could argue that there's a fairly major power imbalance on both sides (one becomes the King of France, regarded as being ordained by God by all the unsuspecting courtiers etc., and one is older, wiser, rescued Philippe from the mask - twice - and is now a close and trusted advisor to a fairly naive and sheltered young man)...
Where was I going with this? Ah, yes - well, I just find the dynamic very interesting (whether the pairing is done romantically, paternally - Athos has just lost his son, a man of about Philippe's age - or just straightforward friendship).
I also love the star-crossed, what-might-have-beens of D'Artagnan and Anne. Tragic, yes, but undeniably lovely.
I've seen it once, there's adorable fighter pilots (all fighter pilots are adorable, it's just science) and Tom Hardy was in it...
I am weak, and tragic WWII pilots are my kryptonite. Do with as ye will, dear writer, but I would love a happy ending!
Eroica Yori Ai o Komete (From Eroica with Love)
No, I'm not joking. Yes, I do have a one-track mind sometimes, but tell me it doesn't amuse the heck out of you to imagine Dorian and Klaus road-tripping across mainland USA or Europe, ducking enemy spies and squabbling over the radio, staying in crappy motels that Dorian pouts over because he could afford a lot better but they're trying to avoid notice not announce their presence to every Soviet spy on the continent, and Klaus is very determined that he doesn't need a soft bed to sleep on. Maybe there's a B'n'B somewhere run by a little old lady with very thick glasses who can just barely make out Dorian's long blond hair and, oh noes!, there's only one bedroom left! With one bed! But that's alright, because little old lady is convinced that 'Doreen' is a lovely wife for Klaus, and with such pretty hair!
All of that being said, however, the sky's the limit and I wouldn't be opposed to a case-fic or, indeed, anything else with these two...
Whelp, that's it for now - if you have any questions, just drop an anonymous comment on here, and happy writing. I'll see you in a few months!