I just started the Crying Freeman, which aside from its beautiful artwork and action based plot also has a beautiful character, the Crying Freeman himself.
I just thought it would be interesting to cross The Crying Freeman with Avengers P.I and Captain America: TWS. I think it would be interesting if Clint, Bucky and Yo Hinomura met.
Also, I think it would be awesome to mix S.H.I.E.L.D with Detective Conan and Musashi #9. The possibilities of the Shadow Syndicate and Ultimate Blue? That'd be pretty cool.