I completely agree with Majora's Cat. Darknuts/Iron Knuckles are definitely the best enemies in the Zelda series. They've appeared throughout many of the games, and in each one they have proved to be a great challenge. And I apologize for the long post. I don't expect you to read the whole odyssey of what I think about these great enemies, so you can just skim along if you feel so obliged.
They first appeared in LoZ, and were either blue or orange. Besides Wizzrobes, perhaps, they were the hardest enemies in the dungeons. There was nothing more fun than strategically working through a room of about 8 Darknuts. Killing an enemy such as a Stalfos or Keese with a simple sword slash gets quite old, so Darknuts added a refreshing new way to defeat an enemy, as they could not be attacked from the front. Sure, they could be really annoying to face when you weren't used to them, but after a while they became a pleasure to see because of how fun it was to strategically kill them, whether it be with the sword or with bombs.
When it came time for us to play AoL, the Darknuts had received a new name, the Iron Knuckle, and in my opinion, a much cooler sounding and appropriate name. Because of AoL's difficulty level, most enemies were not fun to face, such as the persistent Bago-Bago and the powerful Daira's (who, actually, honestly became fun after I was used to them). But either way, the Iron Knuckles provided a fun fight for the second game in a row. They actually had a brain, so they were able to counter your attacks my moving their shield up and down. This provided a good challenge, while not being too frustratingly hard in my opinion. After a couple of dungeons, I figured out the good ol' jump and slash trick against these guys, which made them a quite convenient 50-100 points. The blue ones integrated the whole sword beam thing, which provided a MUCH larger challenge than the oranges and reds, even furthering the already high fun factor of facing these guys.
After an absence from LttP, the Iron Knuckles returned in LA, now again with the name of Darknut. Now, in these games, they weren't quite as much of a challenge compared to what they were in the first two games, but the thing that made them cool was that there were 8 (if I counted right) ways to kill them. Whether it be with the sword, boomerang, hookshot, pegasus boots, you name it, you could kill the Darknut, and it didn't get repetitive and boring to kill them like other enemies were.
Nintendo called them Iron Knuckles again in OoT/MM (boy, they're quite bipolar aren't they?). Like the first two games, the Iron Knuckles were one of the elite enemies in the game, and perhaps the most elite of all in OoT/MM. They don't appear until very late in OoT, and pretty late in MM, and for a good reason. One swing of the axe took away 4 freaking hearts. At that point in the game, that's about 3 hits and you're toast. Because of this, we had to be very careful maneuvering around these brutal powerhouses. We had to fake them out, wait til they slash, and then proceed to bust them apart. They provided a great challenge, and it is quite unfortunate that they only appear in a few limited places. But either way, they were easily one of the most fun enemies to face.
I don't really have much to say about the OoA/OoS. To me, they seemed like slightly more challenging versions of the ones in LA, or at least there was a variation of them that was more challenging. However, they returned in TWW, as Darknuts. The Darknuts in this game were the enemy that you could most easily use the parry attacks on (I think that that's what they were called, the glowing A button attacks). As we progressed through the game, they became red, and then gold, each posing a higher threat, and making them more fun to face. I didn't find them to be as fun as they were in OoT/MM, because with the whole parry attack thing it made it easier to beat them. But they still, once again, proved to be one of the more elite and fun to face enemies in the game.
In TMC, they were almost graphically identical to the ones in TWW, but since they were on completely different platforms, they had a much different experience combatwise, and once again, there were one of the most challenging and elite enemies in the entire game. In TMC you had some freedom as to how you beat them, as you could roll around them and use all kinds of different sword moves learned from scrolls. Bombs also worked on them, more effectively so than they did in LoZ, and was another interesting way to defeat them.
To date, the final game that Darknuts appeared in is TP. The way you killed them was quite reminiscent of TWW, as you had to break of their armor before actually defeating them for good. The Darknuts were quite difficult in these games, but weren't the beasts that they were back in the days of OoT and MM. I haven't played TP in a while and can't remember if they appeared outside of the miniboss in the Temple of Time, but it was still fun to defeat them strategically. Many sword techniques were fun to use against them, such as the mortal draw. And once again, the Darknuts were very intelligent enemies that used their shields very strategically to defend, and thus, were once again, an extremely fun and difficult enemy to kill.
So, throughout the different Zelda games, the Darknuts/Iron Knuckles have proven to be the powerhouse of the series, reappearing again and again so that I can have the joy of carefully annihilating them.
