So, I think everyone agrees that The Megalovania Sans Fight in the Genocide Run is the hardest Battle. But which one has second place?
The Battle Against a true Hero Undyne Genocide Run Fight?
What is your opinion on the three Hardest Undertale Fight?

So, let us say Undyne's Genocide Battle is second hardest.

Then the Genocide Run has number one and two of the hardest battles.
Would that make the Genocide Run harder than the Pacifist (not true Pacifist) Run?

Well, you have to fight less monsters, Most just flee before you get there or are like Mettaton NEO.

Which is the hardest Run? (Don't include that Genocide is hard because Empathy, etc).

And...

Which is your Favorite Run?

Which is your Favorite Character?