Zelda 2 was actually fun once you got past the fact that enemies NEVER dropped health and fairies were only in 1 section of each dungeon(if you were lucky) and would dissapear after using them until you left the dungeon and reset the entire thing.

As far as TMNT goes, I haven't beaten it, though I have gotten to the Airport level that comes right after the one where you get to drive the turtle van. I actually didn't find it at all difficult to diffuse the underwater explosives (once I got the hang of it, but yeah, it was a pain up until that point)

I beated COD 2 and COD 4 on Veteran Last week and I can assure you......I DON'T MISS IT X_X.

I beat TMNT when i was a kid but it took me forever.  I bought it when it first came out for 50$, At least i can say i was able to put a lot of time into it.  The new game by the same name TMNT is one of the easiest games ever made.

Has anyone considered the part TIME plays in this particular discussion?

Sure, it was great to have games that took you months to practice until you finally are able to beat them... when you only had the allowance to get 1 game a month.

Now I'm finding that I'm playing all sorts of different games and I have enough trouble putting in the time to crunch through them as it is. I wouldn't mind a difficulty slider, so I can give myself a challenge after I beat it the first time though, I just wish the difficulty sliders would actually be designed to make the enemy ai smarter instead so I have to think, rather than just handicapping my health or boosting the enemy's damage to me, etc.

Zelda 2 was the devil, I don't care what anyone says

Man, SCREW Darknuts in that game, seriously

I hear you, man. it was fun, but only because I was using an emulator for the DS that allowed you some 30 seconds of rewind at any time. Even with that, it was still insanely difficult. Even worse than the battles are the inanely obscure clues as to where you're supposed to go and where you need to find what items you're looking for and such.
Do you know you need to find every one of those stupid magic potions that increase your magic bar in order to progress through the game? It's actually one of the freaking requirements for a critical spell, and it's a spell they don't even TELL you that you need. I got all the way to the pain in the butt boss for that dungeon and tried to fight him for like half an hour and couldn't do a thing because you need the spell to even be able to touch him!

Or wait, maybe that was the spell that you needed to rescue the kid to get.