Sephiroth is definitely overrated but I don't think he should be underrated. Maybe not #1 but somewhere in the top 10.
Bowser is kinda of a bitch really.
and I hate wild zubats!
No one knows the best 100 villians from video games because we all have our own best 100 villians of video games. The list is fun for looking at what "people" think the best villians are.