As for Sephiroth, I find him to be a much less intriguing clone of Kefka.
Hm, you've got a good point there. Kefka is both insanely evil and sort of funny at the same time.
Changed votes;
1. The Bioshock-man (He can shoot bees! That beats everything!)
2. Giygas/Giegue, Mother-series
3. Kefka, Final Fantasy VI
4. Golbez, Final Fantasy IV
5. Solid Snake, Metal Gear-series