I figure I should use this post to give some extra info on my preferences.
In general I prefer for crossovers to be gen. I understand if that doesn't work for you, but just thought I'd mention it ;-)
I'm mostly a multishipper in most fandoms, just please if you write a teen wolf fic, please no sterek or steter.
My favorite Supernatural character is Dean, and I love his relationship with Sam and Cas and everyone else. I love stories that have the Winchesters face off against law enforcement, or that have them go after supernatural beings. (in general I love outsider pov regardless of the fandom involved)
I've watched Supernatural up to the finale of s13, so no worries about spoilers.
As far as NCIS and Criminal Minds are concerned, I mostly love them for the outside pov they offer on the more supernatural tinted fandoms like Supernatural and Teen Wolf. Though I do love all chars on both shows.
Teen Wolf is my biggest current fandom, and for me, it's all about Scott McCall. He's my main fave on the series, and the reason I watch it over and over and over again :-)
So really it woudln't be a Teen Wolf story without him in a major role. I love his relationships with everyone on the show, (and though I ship scerek, sceo, sciles, scallison, scira... and pretty much all Scott ships, I'd still prefer a gen crossover)
Please no character bashing, main character death, or sex between an adult and an underage character.