Well that sucks that you can't find your OoT cartridge...
I've finished it twice. once on the original, and the 3DS version. I once got stuck in on the Fire Temple where you have to run up to the chest with the mallet. people dread the water temple, but the Fire Temple I feel is where the difficulty spikes with the dragon boss
I finished The Wind Waker in like 3 days without a single game over, though There was this one lookout with 3 Wizzrobes that gave me a run for my rupees (sorry

). the bosses at Ganondorf's lair were nasty too.
OG game and A Link to the Past had dungeons, enemies and bosses that got on my nerves at times, but completing them are so rewarding!
I need to find time to play Twilight Princess and Skyward Sword too, but I hope all the swinging in the latter doesn't aggravate my right shoulder...
I also need to buy the others some day too. Spirit Tracks was an absolute train wreck though (pun not intended)