I think Ron Teufel won best abs five consecutive years in the AAU Mr. America contest.  I remember seeing a Muscle Builder magazine cover of Pierre VanDenSteen displaying incredible abs. 
Those guys really stood out to me.

Two great picks.

Nubret had good abs for golden era. Franco had good abs, his oblique tied in to his serratus and abs giving him a good ab pose.

For the mass era Paul Dillet had good abs.

I think the very best have all been mentioned Pastel, Priest, Tinerinno, Makkawy,  Tufuel, Bill Grant.

Alot of people say Zane but his abs looked weird.

Saw a recent vid where the dude said the healthiest diet is on with good quality lean protein and fresh fruits and veggies
 
Gotta agree that's spot on

So since I eat 3 meals a day meal 2 or 3 will be white fish with fresh fruits and veggies

My meal one is always coffee made from milk not water with sugar

Seems each meal should have at least 30 grams of protein to "cross the leucine threshold" oh brother 

my diet is fresh juicy well rested pussy in its own juice with panties to the side and a little ah jus gravy in the back soiled it’s really high in fiber and protein and it also builds the strongest muscle in the body, the Lengua ( tongue) for those who are culeros 

I think Ron Teufel won best abs five consecutive years in the AAU Mr. America contest.  I remember seeing a Muscle Builder magazine cover of Pierre VanDenSteen displaying incredible abs. 
Those guys really stood out to me.

I keep seeing "Kevin Levrone is hittable" for some reason.

I'm shocked he's still alive.