the best crossover shows you probably will never see. different networks.
Law and Order SVU vs. Castle...both shows are set in NY.
but the one I'd pay to see is:
NCIS vs. Bones, both set in DC...
Bones and the squints meet Abby and Duckie.
Booth meets Gibbs.
sniper vs. sniper
who takes the shot ?
( obviously the musings of a very strange mind)
( the mad one shakes his head, he's forgotten where his bridge is)