Schwarzenegger easy. The guy's got screen presence and charisma. He can make crap dialogue funny with his tone of voice, accent and facial expressions. He make mutilate himself onscreen non chalantly and make it look plausible and if you tally up his films he's probably got the highest kill count.
Lastly he's played the most quoteable characters ever.
"I'll be back"
"Remember when I promised to kill you last? I lied."
"Come on Bennett, let's pahty!"
"Stick around"
"Get to da choppah!"
"You are one ugly mudda fugger"
"Well I hope you left enough room for my fist because I'm going to ram it into your stomach and break your goddamn spine!"
"Uplink! Underground! Uplink! Underground! Uplink! Underground! Keep it up and I'll uplink your ass! The you'll be underground!"
"You're luggage"
"It's Turbo time!"
"God ordered a hit on an investment banker?"
"Between your faith and my Glock 9mm, I'll take the Glock"