Machete or Katana?

Budget and use is important. Machetes are much cheaper than a katana and katana is much more expensive than a machete. If you found a katana at machete price then it probably has wrong type of steel, poor design, and horrible fitting. Essentially it would not be functional at all, and probably wouldn't even serve as a decoration. If you are looking at a machete at a katana's price level, then it's not going to be worth it. No machete is worth that much money.

If price is no consideration, then it is about use. What are you looking for? Do you want to own something that can be used against another melee weapons in combat? Then katana. Are you looking for a tool that can serve a utility purpose and can be used against unarmored and non-melee armed opponents? then machete will do. Katana is too finely balanced for serious utility use, and machete is too thin to be used in heavy melee combat.

There was this guy that wanted to grapple and I fell on his leg.

Depends on task at hand.

For what?

Katana of course, it's a freaking 4' razor blade.

for what? a sword fight in feudal japan or a "people's revolution" in latin america? different blades have different purposes!

Any