What was your best Villain and why?

[Iczer]

The team was freshly formed.

Scorpion, a construction worker from queens with his armoured skin and expertise meant that the base was an evolving construct,m suited to their needs.
Chaser, the ex cop, whose time manipulation powers meant that any one he chased, was caught.
Gecko, the sneak. Channeling the power of the diminutuive reptile meant that this agile mutant would always keep the team apprasied on the enemy.
Vague: the anonymous back and organiser. His powers were simply to seem unimportant.
Wires, the tech expert. A prodigy genius hardware electrical guru meant the base was well surveiled, and that all information could be collated, organised and examined with a thoughouness that allowed the team to pull together.

And then there was Stickman. The loner vigillante type. a Black suited frenchman, whose paired truncheons and acrobatic skills made him a master in hand to hand, but his dour ways and uncommon knowledge of the seedy underworld made him...untrustworthy.

As events rolled out, and missions came and went, the team became more and more distrustfull of the cocky Frenchman. They had him followed, surveilled and photographed. And when the local crime boss, 'Big D' ambushed the players there was a surity after thier narrow escape that Stickman was a plant.

He wasn't. Wires, the surveilance guy had been in Big D's pocket the whole time. While out and about, wires rigged the base to blow and burn, stole a metric truck load of Vagues Future weapons cache and fled. he works for Big D now. and Big D knows all the players strengths and weaknesses.

The players have a Mad on to get Wires now. Sure, Big D is a bad guy, and a scary one at that. his Hired muscle is a challenge if one is not prepared, and Big D may or may not a metahuman himself. But wires has furnished them with solutions.

Scorpion is vulnerable to magnetics and electricity
If not given time to rest, Gecko can be overwhelmed with damage.
Chaser, who needs to catalyse a palladium/cobolt mix in his blood cannot access the hieghts of his speed while cobolt needles are in him.
Vague, while invisible to camera's, and hard to notice at the best of times, has her bike rigged with a tracer, as well as her armour, and her implant computer is vulnerable to transmitted feedback.
Stickman...well stickman was, after all, just a man. He died in Big D's ambush. Trapped in station wagon while it burned around him. he was never a bad guy, but he was a Jerk, and an easy frame for wires to deflect suspicion.

Batts

[Misfit KotLD]

That would be Guzman, a Mystic Knight with a BFS and a gang of slavers. While the group waded through the mooks (they're mooks, after all), the party was unable to pin down Guzman to finish him. Included in the attempt to capture Guzman was the party Mind Melter posing as a captive slave for sale by the NPC Gunslinger (who is a scummy bastard). Chaos ensued and the bad guy got away. The party sorted out the chaos of Guzman's camp which included a number of girls captured from a PC's home village. The slaves get sorted out and sent home, now very well armed. The party hunts Guzman down and catches him in Mexico on the coast of the Gulf of Mexico. This time they get him pinned via CoA. A gang rush follows and the party Psi-Ghost decides to join the melee and gets sworded. The party backed off and shot the **** out of him, Guzman died. But damn did a big villain turn into a headache for the players.

[dark brandon]

My best villain was an NPC for D&D 3.5. A goblin rogue-shadow dancer. He wasn't "Villanious" as "just works for the other guy", but his skills were high enough that he could torment, throw hints and such things from the shadows.