I beat all of them some years back. Battletoads was fun for the 5 hours or so it takes to beat it, some challenge to be had, highly overrated game overall, though. I never found ghouls and ghosts hard, like.. at all, in fact I never found it to be a good game either.
You can disagree, we all find challenge in different places.
hmm well battletoads was way harder for me because i was using a joypad and the second last stage you really need a proper nes controller to do it properly, now dragon's lair is a broken game have you played that? also i don't know if anyone else does but i love watching gamecenter cx the japanese retro game challenge show with english subs on youtube, obviously it's on fuji tv in japan but they are getting uploaded with fan made subs on youtube.