That would have to be the Desert Colossus in Shadow of the Colossus. It was like boarding a train. Very epic.

I'd say Jack Krauser from Resident Evil 4.

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Kain: Conscience...? You dare speak to me of CONSCIENCE? Only when you have felt the full gravity of choice should you dare to question my judgment! Your life’s span is a flicker compared to the mass of doubt and regret that I have borne since Mortanius first turned me from the light... To know that the fate of the world hangs dependent on the advisedness of my every deed -- can you even begin to conceive what action you would take, in my position?

Raziel: I would choose integrity, Kain.

Man, I have yet to play that game. I want to so bad.

But I heard you first have to play ICO. Is that true?

Not technically, but Shadow of the Colossus acts as a kind of prequel.

When Oogie Boogie turns into a house in Kingdom Hearts.

Man I hated that house thing. I think. Anyway I'd prolly have to say the bosses in the zelda games from the Ocarina series and Windwarer and Twilight Princess. Particularly Ganon from OOT and Gannondorf From Windwaker. Maybe not the battles themselves but the final blows. They rocked!!

O and speaking of Kingdom hearts I forgot about sepiroth. He was the funest boss I've fought in a while although he wasn't part of the main storyline. He was hard to beat in KH until I figured out how to kick his tail and even harder to beat in KH2 despite knowing how to do it lol. So he's my vote for funnest and most challenging boss. I like the bosses that challenge my gaming skill but aren't too out of my league. He was perfect.

I liked to go through the twinrova episode in OoT. I found the whole spirit temple thing no just humorous and entertaining, but quite deep too. The fire/ice thing with the mirror shield always excited me. Oh, let's not forget Ganondorf/Ganon as well! man, I used to LOVE doing that boss fight, and the cutscenes were great. They nailed that game.

I think some of the Star Fox 64 Bosses were funny to beat up xD