17 and 18 would have made better villains than Cell IMO. You can even keep the part where they end up not being pure evil, just kinda petty and confused.
I never liked Cell, and as time has gone on I think my opinion on the Cell saga as a whole has degenerated quite a bit. It has some hype moments, buried under a lot of trash. I actually think the Buu saga overall is better than Cell.
Cell as a villain is a big part of this. Or, at least, Semi-perfect and Perfect Cell are. Perfect Cell is just Frieza 2.0, and Semi-perfect is too single-minded to really be an interesting villain.
Imperfect Cell is indiscriminate enough to be interesting. Truly monstrous in a way the other forms aren't.