Top Ten lists are tough, so here's a top 5...or bottom five, really.  Enjoy:

5. King K Rool (Donkey Kong Country games) - King K Rool was one of the stupidest villains...he didn't seem like he ever had an intelligent plan, and he looked way too goofy to strike any sort of fear into the player.  I've seen inconsequential villains in other games that are much more menacing and diabolical than KKR.

4. Lavos (Chrono Cross) - In Chrono Trigger, Lavos was a badass.  Not the most story driven, but basically a giant parasite that was feeding off the earth to gain enough power to eventually rain destruction on the world.  Unfortunately, Lavos' role in Chrono Cross seemed to only be to be the final boss.  A very tenous connection to the first game, and almost offensive that we should somehow buy in that this game was a legitimate sequal to Chrono Trigger.

3. Dr. Robotnik (The Sonic games) - For such a beloved (and fun) series of games, you'd think the main villain would have gotten a little more storyline.  What little story that can be pieced together about Robotnik seems stereotypical and cliche, unless I missed something.  Which I highly doubt.

2. Yu Yevon (FF X) - Sin was cool.  Not the most innovative thing, but cool.  Jecht was a badass who got his own hard rock music during his fight...also cool.  Then, the climax of the end sequence is...a tick.  All that gameplay, all those bosses and badasses, and you end up fighting a tick.  Talk about anti-climactic. 

1. Human Raziel (Soul Reaver 2) - Barely even counting as a boss, the big climax to SR 2 ends up being....that you can't lose the fight.  While the storyline of that move was kinda cool, I didn't believe the game had actually ended.  I know you don't have to have some big bad villain at the end of a game always, but this just seemed lame and like a cop-out.

10. Magus (Chrono Trigger) - Although his role as a villain does not last forever, even when he is aiding you Magus still has a sinister aura about him...and no matter what he says, you always feel that there is some underlying reason for his actions that he's not sharing. Unfortunately, his role in Chrono Cross was cut, so further development of his character was hampered by Square's overzealous hands.

9. Seymour (FF X) - Seymour starts out as a somewhat cookie-cutter creepy mage villain, but his backstory make him the most compelling villain in FF X.  The tragic events of his past that turned him into the monster that he was made him a little more well rounded than, oh, let's say Sin. 

8. "The Titan" (Sixteenth Colossus) (Shadow of the Colossus) - A huge moving, living tower that can fire huge fireballs accurately across the sky and who you must climb up to defeat. Story wise, not a very strong boss (why were these Colossi created? Are they sentient?), but visually this is one of the most impressive and daunting bosses in modern video games.

7. Ghaleon (Lunar: The Silver Star) - Formerly one of the legendary heroes, Ghaleon's mad desire for power led him to kill off some of the other legendary heroes and leads him to resurrect the goddess Althena for his own personal use.

6. Big Smoke (GTA: San Andreas) - C.J.'s former friend and mentor, Big Smoke's conversion from staunch stoner friend to paranoid, body armored stoner who wants to kill you and take over Los Santos and make it (basically) his own personal drug creating sweatshop is something to behold.

5. Officer Tenpenny (GTA: San Andreas) - Corrupt cop who can outsmoke hippies and is voiced by Samuel L. Jackson? It doesn't get better than this in non-RPGs. Officer Tenpenny is a smart muthaf*****, and you shouldn't take him lightly. Especially when he gets his hands on a little of the "wet" ;)

4. Bosch (Breath of Fire: Dragon Quarter) - Former ally and member of high ranked nobility, Bosch's fall from grace is both tragic and frigtening. Having been outmatched by Ryu, Bosch's lust for power turns into a deeply rooted obsession with killing Ryu. (If you can't tell, I like flawed/insane villains most of the time).

3. Ganon/Ganondorf (Zelda games...almost all of them) - Has there been a better recurring villain in the video game universe? Always power hungry with a taste for death and destruction, Ganondorf's endless pursuit of power across many different Zelda universes makes him a force to be reckoned with.

2. Sephiroth (FF VII) - Perhaps the most well-known RPG villain in video gaming history, any list of the best villains must include him. Unlike most, however, I feel there's just a little something lacking from Sephiroth...a little something that Kefka possesses that Sephiroth doesn't. Could be the complete mania that is Kefka's character, the bizarre insanity that leads him to unwonton destruction. Sephiroth seems too grounded in his goals, however evil they may be. That's not saying he was a bad villain by any means...he's probably the last great new villain in the video game world. He's just not quite...

1. Kefka Palazzo (FF II/VI) - A maniacal clown who receives the power of a demi-god and then proceeds to use that power not to rule, but to destroy at whim? An androgynous megalomaniac with delusions of grandeur and the dream of creating a monument to non-existence? It seems to me that, on the scale of pure evilness, Kefka ranks at the top of the list. No other video game villain that I've seen has had the pure, unadulterated evil that Kefka possesses.