Vs. Marx - Kirby Super Star (SNES, DS)
The first time we lay eyes on Marx, a cute little jester-like being resembling a Goomba, he fills us in on the story of the final unlockable game in Kirby Super Star, Milky Way Wishes. The sun and the moon of Pop Star are fighting. In order to make them stop, Kirby must collect power from the Dream Springs of nearby planets in order to summon Nova, who can grant any wish. The wish was to make the sun and moon stop fighting but just as Kirby is about to make the wish, Marx pushes him out of the way and instead wishes for complete control of Pop Star. Marx was playing Kirby from the very start. He got the sun and moon to fight and he got Kirby to do his dirty work for him. Once Marx gets his wish, he transforms into a hideous bat-like creature with a creepy laugh. Marx is famous among Kirby fans for being the manipulator that he is and for his battle them. Years later, Magolor would pull Kirby's strings in the same manner that Marx did in Kirby's Return to Dream Land.
The Evil Lord Exdeath - Final Fantasy V (SNES, PS, GBA)
Exdeath isn't as developed a villain as other in the series, but I still like him anyway. I mean, how many mages in the Final Fantasy series are wearing armor and fight as if they were knights? Whenever he shows up, he slaps the party members around just fort he fun of it. This isn't Exdeath's battle theme, but his standard theme that plays whenever he appears on the scene. When you hear the first few notes of this theme, you know something bad is going down.
Ultimate Koopa - Super Mario 64 (N64, DS)
Bowser was quite the pushover the first two times you fought him. But for round three, the kid gloves come off. It isn't as easy to to grab Bowser by the tail as it was before, and when you do manage to throw him into the bombs twice, the battle arena reshapes itself into the form of a star, which makes landing that third and final hit much more difficult. I personally feel this is one of the best final battles in the Super Mario series, if not the best. I wasn't expecting a organ to be blaring during the fight, but it made for a great grand finale fight piece.
Theme of Seven Force - Gunstar Heroes (GEN)
Under any list of awesome video game bosses, Seven Force is generally always somewhere on that list. Piloted by Green, former member of the Gunstars, the mech known as Seven Force can transform into seven different forms such as a phoenix or a pistol. If you're playing on the Expert difficulty, you'll face all seven of Seven Forces deadly transformations. So great is Seven Force's popularity, that he's been used and referenced in other Treasure games like Alien Soldier and Astro Boy: Omega Factor. His boss theme ain't too shabby, either.
Doomsday Zone - Sonic 3 & Knuckles (GEN)
Get all the Chaos Emeralds (just the Chaos Emeralds. Super Emeralds aren't required) and you'll get to play the final zone of Sonic 3 & Knuckles, the Doomsday Zone. In what is one of the most memorable boss battles of the entire Sonic series, Super Sonic flies through space in pursuit of Dr. Robotnik who has the Master Emerald, the source that keeps Knuckle's home, Angle Island afloat. You have to maneuver Super Sonic so the missiles Robotnik shoots at him hits the cockpit of Robotnik's flying mecha. You also need to collect enough rings to keep Sonic's Super form active so he doesn't die. As cool as this final battle was, it was responsible for setting a standard that would continue in later Sonic games where Super Sonic could only be playable during true final boss battles, much to fan's annoyance. Though with Sonic 4 and Sonic Colors, this trend seems to have come to an end.
Yell Dead Cell - Metal Gear Solid 2: Sons of Liberty (PS2, XB)
Casting aside Solid Snake in favor of newbie Raiden was a bold move, one that fans still whine about to this day. I personally had no qualms with Hideo Kojima's decision to place Snake in the mentor role and Metal Gear Solid 2 is actually my favorite Metal Gear game. It's the only one I've beaten on every difficulty setting and gotten every dog tag. The members of Dead Cell were even more screwed up the the Fox Hound crew from the first Metal Gear Solid, but they had a much better battle theme, which was reused as one of the tracks to be played on the Shadow Moses battle arena in Super Smash Bros. Brawl.
Boss B - Star Fox 64 (N64)
Fox McCloud and his crew spoke in incomprehensible gibberish in the original Star Fox on the SNES. When Star Fox 64 rolled around, you could clearly hear every word that was said without having to look at the text to understand them. The gameplay was also a lot smoother and the auto targeting system worked liked a charm. Of all the boss themes in Star Fox 64, Boss B sounds the most intense. The way the drums are pounding like crazy, it makes you feel like you're in for the fight of your life. Star Fox 64 received a visually updated port on the 3DS with arranged music, and it's not too shabby but I still prefer the original score.
The lord God - Capcom vs. SNK 2 (ARC, PS2, XB)
Capcom may not be the company that it used to be, but I can look back on their past efforts and smile. Capcom vs. SNK 2 is one of my favorite games in Capcom's crossover series, bringing together even more characters from both company's sizable roster. This intimidating piece of music plays on the final boss, Ultimate Rugal. Rugal has always been a force to be reckoned with, but in this game, it was taken up to eleven.
My Name is Songi - Legend of Legaia (PS)
While waiting for the release of Final Fantasy VIII, I picked up Legend of Legaia in early 1999. I greatly enjoyed the combat system of fighting with martial arts as opposed to the usual swords and such that a great deal of RPGs use. One of the three playable characters, Gal, had a rival in Songi, who has one of the most incredible boss themes I've ever heard. There's quite a build up before it gets to the main chorus, but that build is almost as awesome as the main chorus. The soundtrack version of this theme is sadly, not looped so this is one of those rare instances, where I'll link an extended version.
Wily Battle - Mega Man IV (GB)
What would you say if I told you that the best Mega Man Classic battle theme lies not in the console versions but one of Game Boy games? Don't believe me? You probably haven't heard this theme then. Despite using bosses from the console games and some shrunk down versions of those robot master stage themes, there was some original music and it gave the console versions a run for their money, Wily Battle being one of those themes. Fans certainly have taking a liking to this song as it's been used in a number of Mega Man ROM hacks. I'm hoping the rest of the Mega Man Game Boy titles make it to the 3DS eShop.