Unique bosses.

[Beatrix]

One of the bosses in the last level of Ninja Blade.

He's so huge that you start out fighting him an attack chopper, then he takes that down and you fight him from the top of a skyscraper until finally you get his health down low enough, run up his sword and kick him in the face!
Yes, it was that awesome.

 

[Et3rnalLegend64]

Most of the bosses from MGS 1 and the bosses in MGS 3. Although, the Sorrow sequence did kind of creep me out. But that might be linked to the fact nearly everyone i met in the game i ended up ending the life of. So...thats probably why.

We should say screw it since the large majority of MGS bosses count. Psycho Mantis, The End (or at least the number of ways you could kill him. Not to mention it's more of a battle of attrition rather than a straight shoot up), The Sorrow, Laughing Octopus, Screaming Mantis, among others. Take note that a lot of these bosses take the Fourth Wall and shatter it into tiny pieces.

 

[HalfCaptainRob]

Honestly. The bosses in the Ninja Gaiden games. Why?

Well, because they don't have some gimmick that you hum and haw over, get killed a few times, figure out the oh-so-exploitable weak spot, be forever the master of said boss.

The bosses in Ninja Gaiden were. Well, real bosses. They were badass sons of bitches that gave absolutely no ground. You know that annoying attack that makes them immune? Well, here's a one second window to attack in between then, and then instant death.

Well. Most of the bosses. Some are just easy, and some do have the exploitable weak spot. But it's fun actually fighting an enemy that's like you in the sense of it has a guard, it has attacks. It can kill you just as fast. No quick-time events or anything. Just being awesome.

 

[Arcane Azmadi]

Although all the bosses in Shadow of the Colossus were basically beaten the same way (find the weakpoints, climb on the colossus and stab the weakpoints until it dies) most of them are INCREDIBLY unique. Special kudos goes to Phalanx, the amazing 13th colossus which flies high above the desert- the moment when you ride your horse alongside it as it draws low to the ground, leaping from the back of your mount to grab onto its wing and pull yourself onto its back as it soars high into the sky again, is worth an entire game's worth of awesome.

If you want an ORIGINAL boss, they don't get much more original than the battle with the Viola AI-possessed Ardjet from Zone of the Enders: the 2nd Runner. Because you can't harm Ardjet you have to time your attacks to parry its own until you get an opening to grab it and let your own frame's AI attempt to delete the Viola AI from Ardjet's systems.

The battles with Raziels corrupted brethren in Legacy of Kain: Soul Reaver (and his battle with Turel in Soul Reaver) are some of the best and most atmospheric examples of the puzzle boss I've ever played through, especially Dumah.

The boss battles from Legend of Zelda: Phantom Hourglass were absolutely awesome, especially the way some of them used the top screen. Most notable was the invisible boss which chases Link around the arena, and the only way to hit it is to aim via the boss' own first person view displayed on the top screen- when it charges Link you have to aim your bow until you can see Link aiming right into the camera and then let loose!

Aw hell, just read this list [http://tvtropes.org/pmwiki/pmwiki.php/CrowningMoment/VideoGameBosses] and pick out the original ones.

On-topic: The Bowser fight in Yoshi's Island was pretty unique.

Hell, most of the boss battles in Yoshi's Island were fairly unique. Remember Raphael the Raven? Being chased around the outside of a tiny moon (early shades of Mario Galaxy there) with 2 stakes pounded through it by a large black flightless bird, trying to beat it to the opposite side so you could drive one end of a stake into the surface of the moon, causing the other end to burst out the other side and hit the boss. It was AWESOME. Also see: the Potted Ghost, Prince Froggy and Navel Pirahna.

 

[Sacman]

That girl from No More Heroes that I think wheres a french maid outfit, throws gimps at you, and tries to kill you with a baseball bat that was pretty unique for a boss or the mail man guy that wheres a super hero type costume and has machine gun nipples... but sadly all of the boss battles come down to waiting for them to attack dodging and attacking before they have time to recover...

 

[Evil Tim]

If you want an ORIGINAL boss, they don't get much more original than the battle with the Viola AI-possessed Ardjet from Zone of the Enders: the 2nd Runner. Because you can't harm Ardjet you have to time your attacks to parry its own until you get an opening to grab it and let your own frame's AI attempt to delete the Viola AI from Ardjet's systems.

"Invincible boss you must grapple while [ACTION]" is hardly original.

 

[CD repo man]

Nine-Toes (He also has three balls).

 

[Pegghead]

Well my old boss used to come into the office every morning wearing a tie dye bowler hat and a pair of walrus skin parachute pants, he was pretty unique.

But in all seriousness, The boss fights in Dead Rising were pretty unique, how often do you get to fight guys like grocery store clerks?

 

[Twilight_guy]

This guy:

How many other bosses do you beat by literally throwing there own minions into the camera at them?

 

[jonnopon3000]

I think the juggernaught or whatever it is called in Price of Persia Two Thrones.

Awesome boss.

Spoiler: How to kill it

Climb up to a place where you can leap towards it, then activate a quick kill sequence. There are three of these wherein he rips off an arm, stabs out an eye and drags the blade down its back. Then you run up its back and plunge his head. It is truly awesome.

 

[Ultress]

The first boss of Donkey Kong country 3,it was a giant barrel that you killed by making him burp himself into a hole. Then again the entire DKC series had quite a few gimmick fights and scads of gimmick levels but most were interesting

Spoiler: Ninja gaiden 1's final boss

He was fairly unique in game for being a total pussy that didn't block the fly sparrow move constantly

I'll think of more later.

 

[MattyJ]

Mysterio in Spider-Man 2 on PS2.

 

[jdogtwodolla]

Banjo Kazooie 1 witch boss. i never actually made it to her but but the statue part didn't seem very orthodox.

 

[Hristo Petrov]

The Big Mighty Poo from Conker's Bad Fur Day

 

[jdogtwodolla]

Oblivion's Grey Prince battle. if you did his mission he just let's you kill him, but it counts as murder.(my bad for double posting if somebody doesn't like that)

 

[scrambledeggs]

As aforementioned:
SOTC
MGS1 and 3.

However, most of four's bosses weren't that interesting for me. Except for the final battle. Watching those health bars, hearing those themes... it sent shivers down my spine. I love Metal Gear Solid soooo much.

I thought the final boss in Onimusha 2 was pretty amazing, as well.

 

[Amarok]

The Shade of Aran in World of Warcraft: The Burning Crusade deserves a special mention for being incredibly unique within that game (he's pretty much the only boss who has no aggro table at all, and merely lobs spells at whoever happens to have the lowest hp at the time)

 

[lewism247]

Most of the Bosses in MGS4 were fairly unique

Spoiler

Playing hide and seek with Octopus, Tracking down Wolf, having to steal a puppet from Mantis, CQC Vamp to inject him, fighting with Rex and Ray, then an epic fist fight with Ocelot to finish it off.

The boss fights were awesome.The final one was kinda moving.

 

[Gamurga]

The spider boss from Metroid Prime 2 was pretty original. You had to beat him in morphball-mode.

 

[omega 616]

Most of the Bosses in MGS4 were fairly unique

Spoiler

Playing hide and seek with Octopus, Tracking down Wolf, having to steal a puppet from Mantis, CQC Vamp to inject him, fighting with Rex and Ray, then an epic fist fight with Ocelot to finish it off.

You forgot raging raven.

Spoiler

You didn't steal a puppet, you took them so she couldn't control the living (like psycho mantis) and the dead (the sorrow), once you took them away, equip the mantis doll and shoot her with it, shake the controller to finish her off.