Arnold VS Stallone

I say put them in a boxing ring and last man standing has my vote.

As an actor, Stallone.

In terms of acting, my pick is also Stallone. However, when the deciding factor is their body of work, then I'd go with Ah-nuld.

Best work:

Sly:

Cop Land (also think this was by far his best acting performance)
First Blood
Rocky

I think especially Rocky has not aged very well. I saw it nearly 30 years after its release and at the end, I was thinking: I've seen this before... And this is one of Stallone's best movies so...

Governator:
Terminator
T2
Predator
True Lies
Total Recall
Commando (crazy fun xD)
Both Conan movies (crazy fun to watch, especially when he punched that horse xD)

So based on their body of work, Arnie by a mile.

That Rocky movie looked familiar because every time they made a Rocky sequel, they kept remaking it, and it became the formula plot for every sports underdog movie after it.