Not really sure what the hardest game I've played was...
The hardest ones I've BEATEN are probably Ghosts and Goblins and the first Ninja Gaiden, both for the NES. Also beat Ghouls and Ghosts on the Genesis and Snes (quite a fan of that franchise).
There's a number of games I've played that just seemed next to impossible to beat; I don't imagine I'll ever beat Silver Surfer or Ninja Gaiden III for the nes. There's plenty of very difficult games still being made today, but I really don't think they compare.







