Who is the better action actor?

Gibson was good in Ransom/Payback & Braveheart, Willis in Die Hard/Sin City & Pulp Fiction.
I’d give Gibson the nod as far as acting goes, but Willis appeared in the slightly better movies as listed above.
I’m only counting the first Die Hard film for the simple reason that the others were crap.

Willis!

I would not compare them. They are both good.

Mel Gibson is too big of a douche bag for me to be able to think rationally about him, so I’m going to go with Bruce Willis.

Going for the semantics here. You asked who is a better action actor. Bruce Willis is better than Mel Gibson.

They are both awful. But I would have to say Bruce Willis because Mel Gibson is just plain horrible! I can’t stand watching him. I think Braveheart looks like a joke.

I hate them both, but I have to go with Willis on this.
As for Mel Gibson, I heard the screenplay for “Signs” was adapted from one of Gibson’s own scripts, and they just put “Alien” whereever it said “Jew”.

Wherever

I think they are both terrific, but different flavors. Gibson couldn’t do what Willis did in Die Hard, and Willis couldn’t do what Gibson did in The Road Warrior.