Just a little husband and wife debate. She says it’s a toss-up between Richard Castellano and Samuel Jackson Jr. Mine’s James Coburn (after the Carlsberg commercial, the beer drinking world was never the same.)
People I ask are more ‘mainstream’ in their answers: Holden, Bogart, the Marlboro Man, Selleck, Marson (Wayne.)
Ricardo Montalban. No, Fernando Lamas.
Actually…for current actors; I’ve got a thing for Antonio Banderas. For all time, it would be Humphrey Bogart.
Clint.
Clint Eastwood, Lee Marvin & Robert Shaw
Steve McQueen.
Pre-crazy Clint Eastwood is a close second.
Honorable mentions to:
Lee Marvin
R. Lee Ermey
The Duke of course
Chow Yun Fat
Mickey Rourke
Charles Bronson
Robert DeNiro
Bruce Lee
This list is incomplete at best. I’d wager that John Wayne would win in a poll, but that remains to be seen.
All in favor of a poll?
I’d like to nominate Edward James Olmos.
My go-to list includes:
Ernest Borgnine
Burt Lancaster
Robert Mitchum
Sam Elliott
Robert Shaw
Oliver Reed
Anthony Quinn
Armand Assante
Charles Bronson
Kurt Russell
Sorry, but it is Marvin, hands down.
Read his bio, Saipan assault.
Wayne does not qualify, did not serve.
Eastwood and McQueen both did, but nothing like what Marvin went through.
Rourke? You got to be kidding me.
DeNiro? Please.
Bruce Lee? Yeah, ok fine.
It is different if one chooses to fight in a controlled environment with rules rather than face hostiles that are trying to kill you.
Ermey. Different era than Marvin, and I believe he was in a support role in Nam and not in a patrol unit.
Honorable mention: Robert Mitchum. When they were filming The Longest Day the actors were complaining that the water was too cold to jump into–and Mitchum told them to get their butts over the side because if the GI’s could get into the water while getting shot at on D-Day then these precious actors could sure as heck take a little cold water for the sake of a movie shoot.
I’d put Jim Arness on your list, however. At 6’7", he would mop up the floor with precious Bobbie and/or Mickey. Served during the campaign in Anzio.
When Jim Brown was running away from the house about to explode in “The Dirty Dozen,” he was running for his life. No stuntman in the crew could run faster than he can.
Bronson was a tailgunner if I’m not mistaken. Scotty of Star Trek was also a vet. Jimmy Stewart made general and he’s as docile as a kitten.
According to wiki, Bronson served in a B-29 crew in the Pacific theatre, and received a Purple Heart.
Extra points because his real surname was “Buchinsky”. 
William Smith had both macho and geek cred:
Kris Kristofferson, of course.
Acts macho, or acted/acted and did some pretty macho shit IRL?
“Sabu the Elephant Boy” was a ball-turrent gunner
Jackie “Uncle Fester” Coogan flew gliders: into clearings in the jungle. At night.
Douglas Fairbanks Jr. staged fake beach landing to divert enemy forces from the actual landing sites. The enemy would bring the real thing, Fairbanks only had a box of firecrackers.
Victor McGlaughlin probably would have beat 23-years younger John Wayne if the fight in The Quiet Man were real. He’d lasted six rounds against Jack Johnson, and during WWI had maintained order in occupied Baghdad.
Many of the urbane, modest British actors of the 30’s: Basil Rathbone, Herbert Marshall, Claud Rains, Ronald Coleman, had fought in the trenches in WWI, secure enough in their masculinity to wear gray skirts instead of pants.
George Lazenby served as an Army hand-to-hand combat instructor before earning the role of James Bond by breaking a stuntman’s nose during his audition.
Don’t forget the 24 hour Irishman - Audie Murphy may have been small but IRL tough.
I’ll vote for Charles Bronson. My favourite bit from his Wikipedia article: He was considered for the lead in Escape from New York, but he was too tough-looking for the part. (Well, tough-looking and old.)
Audie.Murphy
Neville.Brand
William.Wellman(Lafayette.Flying.Corps)
Can’t really beat the listing above (Lee Marvin is my personal favorite), but one other name to add: Powers Boothe.
The correct answer is Lee Marvin.
A close second is the too often overlooked, Sterling Hayden.
Where is the love for Tim Curry?
Well, if we’re talking real-world, then Robert Ryan. Graduated from Dartmouth, heavyweight boxer while in college, enlisted in Marines and was a drill instructor at Camp Pendleton. He was politically active, a pacifist, stood up to HUAC, and campaigned for civil-rights.
“Ryan often found it a challenge playing sadistic and racist characters that very much were at odds with his own personal ideals.”