Viewtiful Joe in Ultra V Rated... Fire Leo was very hard on that difficulty, but I unlocked Captain Blue.

Henshin a go go baby!

Warhawks when skip and slums are on the same team :D

Ninja Gaiden somethin or other on the Xbox, my friend couldn't beat numerous parts of that game, he'd retry the same area like 15 times, I'd just laugh because I thought he was sucking, he tosses me the controller and I get man handled even worse XD

Pixel Junk Monster when trying to get a rainbow on all stages

commandos series...

ive seen this game mentioned in so many list of hardest games but ive never tried,i might get it if it releases for the VC,im not sure if its released yet

the original Ninja Gaiden on NES. i can't get past the last level to get to the final bosses. been trying for years.

Gran Turismo Series.
Try get Gold on everything.

ive never been able to complete the GT games 100% but also maybe cause the last races are too long

 Let us pray, my brother.

Let us pray. 

Phantasy Star 2 is really tough. Dragon Quest 4, is pretty tough. For jRPGs that's the hardest it ever got for me. Action games, hmm... the first Ninja Turtles was tough for its time, but I managed to beat it a lot easier just a few years ago. The same goes for Blaster Master. Both pretty tough games, though. Double Dragon 3 was tough. Basically any old action game without adjustable difficulty and limited continues was a challenge.

*praying*

i really do hope that it releases outside of japan though