Well this is my first time posting, but I felt like posting my opion on the matter. I've fought many of the bosses that have been mentioned, but I honestly think these are the hardest. So here is my top 5 hardest bosses.
#5: The last boss of Chaos Legion. I have too Admit, the #5 spot is really low on my list. It is a hard fight, that drags on for a long time, but i just don't recall it really handing me a lot of trouble. It was hard, i learned the patterns, and figured out the tricks, and it was still pretty hard even then. It was a test of skill, the entire game was just not something I took to, so I struggled with almost every boss. The fight was harder on the higher setting, but I still beat it, and I never even had too go and get all the stuff in the game.
#4: Megaman Juno on hard. This one might just be me, but for some reason The last boss of Megaman Legends just kicks my ass. I don't know why either. I know his patterns, I've fought him an insane number of times because I love the game, but Juno just always beats me down. I beat him fairly easily on the normal and easy settings, but he is an honest challenge on Hard mode. Again this might just be me, but that's why this is my list after all.
#3: The Nightmare Mother boss on MegamanX 6. This boss was horrid. Evil. The greatest abomination too man and god that I have ever witnessed. The boss is 2 giant squares. Each one takes up a full screen, meaning the entire field of battle is about 4 screens. Not only do they rotate around the room, but drop stuff on you, and while they are shooting at you, is the only time they expose a weak point for you to attack. I had to go back and get all the health tanks and heart items in order to stand a chance of beating this boss. This was all on Normal tho, I do not even want to picture in my mind what horrors the boss unleashes on you on the higher settings.
#2: The 3 face boss on Dante must die mode on Devil May Cry 2. This boss beat me repeatedly. On the other diffculty settings the boss was not overly hard, but on this hardest setting it is the only boss that gave me trouble. He was very tough, but I did manage to beat him. I had to completely change the way I was fighting him in order to win, and had so many healing items that it was not funny. I might just be retarded but he kicked my ass enough too earn the 2nd place.
#1:The Last boss in Drakken Guard's 5th ending. I don't know how many people have played it, but I will honestly admit, it is more than i could handle. It seems easy when you have the concept down, but it gets harder and harder, then blitz you and... well I had to use a trick in order to over come her at last. But that is just me. Some people might not think it too hard, but when I see a post of someone beating her effortlessly, then I will submit, that she was not really that hard.