Kefka and Bowser

Recently? Tialuna from Ys Seven. Hades a close second from Kid Icarus along with Ghirahim.

The final fight with him in Resident Evil 5 did not quite live up to my expectations............

But overall i would have to go with Albert Wesker. (his background, rise to the top and downfall etc)

The various fights with Dracula in the Castlevania games did live up to my expectations though and then some, so Dracula for battles, and Wesker for overall lunatic/nutter/devious/cunning/badass.

first place Liquid Snake, Second place Ganondorf.

Godot. Hands down.

Antagonist =/= villain, of course.

After playing Metal Gear Solid 3, it was Revolver Ocelot.

Runner ups are: The Joker who stole the show in Batman Arkham Origins (best Joker EVER), Seifer from Final Fantasy VIII, and The Origami Killer from Heavy Rain. I like some depth to my bad guys.

Nemesis from Resident Evil 3.

Luca Blight (Suikoden II)

That Giant Hand from Super Mario Brother Brawl.

Plus 'OhMyGosh' from Pyramids of Mars. And Alduine from Skyrim.

Either GLaDOS or my avatar's mask (not Toadette, though she can be pretty menacing)