It would have to be time crisis... the only big name arcade franchises since '94 have been
Ridge Racer, Soul Calibur, Tekken, and Time Crisis
With some less popular ones being: Ace Driver, Alpine Racer, Cyber Sled, and Final Furlong
For a complete list of all of Namco's arcade machines:
http://www.klov.com/...f..._id=&sort=3They've already released Ridge Racer, Soul Calibur has been xplat before and I wouldn't be surprised if it is again, that only leaves Tekken and Time Crisis. Both of which I think would be fantastic on the 360, though both would also need new controllers to be worth playing. (not that any other console wouldn't)
Time Crisis would lend it self really well to the Wii. "A" could take the peddle function, point and shoot with "B"
Losing Tekken exclusivity would be an enormous blow to Sony as that's one of their system selling titles.
They've made other popular games like Xenosaga but none of which also appeared in the arcade.