Is this a real question?
I asked :P
If we're talking number different franchises involved, Project X Zone may take the cake.
That is a game I was thinking about as well. Even though very few of the franchises in Project X Zone (1 and 2) have the popularity of even Zelda's caliber, a lot of these franchises have their respective fanbases such as Soul Calibur, Tekken, Ace Attorney, Xenosaga, .hack, and Tales of.