A few quick likes and dislikes:
Snarky characters, mental or physical h/c, humor, adventure, women or other characters who are usually in need of rescue turning the tables and being the hero, fix-it fic, canon dirvirgent A/Us.
Character death, mundane A/Us, genderswap, mpreg, fpreg, kid fic, curtain fic. Would prefer no background pairings unless they're canon.
Pawn Stars RPF
Rick, Corey, the Old Man and Chumlee
Would love some pawn shop insanity. Maybe Chumlee takes in an antique spell book which turns out to be real (and of course, Chumlee tries casting some spells). Perhaps there's a zombie apocalypse and the guys have to use the stuff in the shop to defend themselves. Please, no real world violence (in other words, zombies, vampires or aliens are fine, but no armed robbers or the like.)
Stewart, Harvick, Kurt Busch and Danica
Team hijinks. If you're looking for specific ideas, perhaps you've seen the Coke racing family road trip commercials? (They're on youtube.) While the drivers I've requested aren't all Coke drivers, I'd love to see them all in a van together going somewhere, with wacky hijinks along the way. Or they get into a bar room brawl. Or they could fight zombies together. I'm not usually a fan of A/Us, but Team Stewart in space could be hysterical. Or the four as a (military?) unit (along the lines of a Stargate gate team.) No serious racing accidents, please.
Michael & Hawke, Michael & Dominic, Michael & Marella, Michael & Caitlin, Michael & Moffet, Caitlin & Marella
Do you get the feeling that perhaps Michael is my favorite character? :) Would love anything exploring his relationship with String, Dom or Caitlin - or perhaps he has to join one of them on a rescue mission? Something about how Marella ended up working for him, or why she's so loyal to him? If the darker side interests you, how about something about Moffet working for Michael/the Firm building Airwolf? Or if you'd like to go another direction entirely, maybe Caitlin goes to Marella for some "spy school" training? Or just the two of them bonding over shared secrets?
Sheppard & Todd, McKay & Todd, Sheppard & McKay & Todd
Todd working with either John or Rodney (or both). Maybe a "cured" Todd joining their gate team?
Denny Crane & Richard Castle, Richard Castle & Rodney McKay, Sheldon Cooper & Rodney McKay, Sheldon Cooper & Walter O'Brien, Walter O'Brien & Rodney McKay
Long before they introduced Castle's father, my personal head canon was that Denny Crane was his father. A one night stand between Martha and Denny seems more than possible. Maybe one or both of the guys find out?
Castle with the gene on Atlantis touching things. Or a wraith killing people in NY. Or Castle finds out about the Stargate program and starts writing a book. Snark between him and Mckay.
Sheldon Cooper or Walter O'Brien sent to Atlantis as scientists/computer geniuses. McKay being McKay. Or maybe he meets one of them at a conference or the like? More snark. :)Sheldon and Walter crossing paths anywhere. Either working together (at least trying to) or totally at odds with one another.
In closing, I hope I've given you some basic ideas in case you want them, but please, if you have a different story that you're eager to write, go ahead. I'm sure I'll enjoy it!