Don't tell anyone, but the sad truth is that I am super-easy. :) I especially love love love LOVE crossovers, so really, you can't go wrong here. Write a story that you enjoy writing and I'm sure I'll love it and enjoy reading it. In an effort to help, I'll tell you my general likes/dislikes and also give a few prompts for the requested fandom combos.
But above all, have fun. If you find that the suggestions feel like a burden, then ignore them and write something that interests you. True passion shines through and makes a story special.
angst, UST, longing looks, the 5+1 format, long-repressed feelings that explode one day, kid fic, roads not taken in canon, zombies, wacky road trips, old friends, handsome strangers, ghost stories, crazy decisions that are right even though they seem so very wrong, 2nd person narratives, porn that reveals more than just naked bodies, unreliable narrators, opening your presents on Christmas Day rather than Christmas Eve, and long deep slow kisses that last three days.
I do not want..
passivity, first-person narration, incest, non-con, non-canon slash, porn without plot, child death or grevious injury, and misusing the words less and fewer.
What I love about each of the shows that appear in my requests:
Mad Men - I love the women, especially Peggy, Joan, and Sally. (It's my headcanon that Sally gets work experience at the office and ends up being mentored by Peggy. I would love to see Peggy flummoxed by Sally's bluntness.) I'm not keen on the Peggy/Stan ending.
Leverage - I love the team dynamic and the witty banter. Eliot is my favorite but I really love them all.
Supernatural - I've only seen SPN up to the end of Season 5. I love the dynamic between Sam and Dean and their banter. I also love Castiel.
Harry Potter - I think the Goblet of Fire is my favorite of the books. I love the richness of Rowling's wizard world. I like all the sympathetic characters.
The Big Bang Theory - I love the friendships here and the characters.
Veronica Mars - Haven't watched this in ages, but I loved the moodiness and sense of place of Neptune. I liked Veronica's scrappiness and shipped her like-whoa with Logan. I also loved her friendships with Wallace and Mack.
Unbreakable Kimmy Schmidt - I love Kimmy's attitude and her approach to problems. I love that she is unbreakable.
General prompts that would apply to any combo:
- A natural or manmade disaster strikes and characters must work together to save themselves and others
- AU - The Zombie Apocalypse strikes - what is life like and how do the characters manage?
- Wacky roadtrip, a la "Planes, Trains, and Automobiles"
- Character backstories - I love a good backstory, especially when it has crossover implications
- The road not taken...what happens when a character makes a different decision than in canon. How does the story (and more importantly, the character) change as a result of the decision.
I hope these idea help spark something for you. Good luck!