Looking at the recent Uncharted thread got me thinking on what you think was the greatest boss battle ever.
Now I'm not talking about who the greatest villain is, but the actual fight (I suppose the character that is the villain DOES have some pull in it though).
I can't think of too many from games I've played in the past, I'll post more if I can, but one for me which was fairly recent was Kessler from inFamous.
My reason for this is that I always play games on Hard mode, and playing through the pretty decent game that is inFamous, I barely saw anything 'hard' about it. When I came up against Kessler I thought it would be easy, but he got the better of me a few times. After a few frustrating losses I got really into the game, both of us jumping around and bashing the crap into each other, it was awsome.
I felt that it really gave you the chance to use a lot of your powers, and gave you a good space to operate in. I also thought Kessler was a pretty good villain.
So, what were your favourite/most memorable boss battles?