Many of the later Final Fantasies take a book out of metal gear solid and have a small infiltration section. Be it Locke sneaking out of South Figaro, Avalanche infiltrating the Shinra Building, The VIII gang in the Missile base or Vahn going to that palace and finding that piece of Magicite.

What was your favourite infiltration mission? From the ones I can remember I really liked running around stealing people's clothes in South Figaro and rescueing Celes, though it's not really infiltration if he's trying to get out. I also liked the Shinra Building and it's plethora of items and the obtaining of Red XIII.