Here are some of the worse boss battles I played:
1) Bowser at New Super Mario Bros Wii.
Do you know the classic cliche where after you beat once the final boss,then something happens and you have to fight him again but in a different way ? Well my battle with Bowser started on a small room where I had to pass him by and reach a button that would take the bridge under his feet,original NES style. I did that,and then that annoying Kamek magician threw his magic dust on Bowser and made him huge,covering the 40% of my screen's real estate. Then you had to do a frustrating platform section to beat him,with trickily placed moving platforms,and you had to do the jumps with perfect timing,something which was nearly impossible considering the huge bowser is constantly moving towards you and throws you fires,so if you take too long he just come so close that he touch you and you die,and the fires he spits are homing,so they follow you around and trying to dodge them usually ends up in such a way that the fire is getting right in between where you are and where you have to jump to,at the exact time that you should jump,making you abort the jump to not get hit by the fire,and getting giant Bowser to touch you and die this way instead! Couldn't it be just an ordinary boss fight without this shit ?
2) All the bosses of Twilight Princess except the final one,Ganondorf.
All the bosses except Ganondorf where very easy and boring in that game. If you didn't tried to die on purpose you wouldn't. All you had to do is wait for the boss to expose its obvious glowing weak spot and attack it. I've been playing a boss fight for 20 minutes without losing a single heart just waiting for the boss to expose its weak spot 5 times to get 5 successful hits.
3) Ganondorf,the final boss of Twilight Princess.
This boss deserves special mention,as this one was the most far-stretched long,nonsenseial,boring fight I had as a gamer. It is because this particular boss fight uses the cliche I mentioned earlier most times than any other boss fight.
First he is on beast form and you must turn to beast form too and fight him.
Normal attacks doesn't do him anything and there was no obvious weak spot at all or any kind of advice and related info by the game,so I had to google the solution for beating him in that morph.So I did,and I beat him to death. But then he just teleports himself and me and Princess Zelda in a valley and suddenly he is up on a horse and me and Zelda up on another horse, and all I have to do is follow him around and get close to him so Zelda can fire magic arrows to him. I wander why he decided to let Zelda free and up on my horse and gave her these arrows..
But that damn girl misses 90% of her shots!!! An extremely large and boring segment here that lasted about 20 to 30 minutes,that didn't presented any real danger and all I had to do was drive around my horse in hope that Zelda will eventually hit this guy enough arrows.
After defeating him in that way too,then I had to fight him in yet another way. Now he was on the humanoid form and pedestrian,and I was on foot too in a circle of fire identical to the one from Ocarina of Time. So now I had to beat him with sword fighting too....
He had block moves,and once more the key to defeating this particular fight was to wait for hours until he leaves his defense open so I can deliver him a hit.
I think this was the longest boss fight I ever had,and the worst of them all.