I would say Reagan, Goldwater, and Eisenhower. (And I would include Taft too.)
Reagan was always willing to reach across the aisle and compromise with the other side.
As Governor Reagan was pro-gay-rights. He vigorously opposed the 1978 Briggs initiative (Proposition 6), which would have banned homosexuals from teaching in public schools.
He was pro-abortion. Six months into his term as governor, he signed the Therapeutic Abortion Act, which led to a rise in abortions in California from 518 a year to an average of 100,000 during his last two years in office.
He was pro-tax. He raised taxes more than $1 billion during his term as governor.
He was pro-illegal immigration. He signed the Immigration Reform and Control Act while president, which led to a rise in illegal immigration.
He didn't join the Republican Party until 1962, before then being an ardent supporter of FDR and the "New Deal."
Robert Taft and Barry Goldwater rallied against "me-too Republicans", and were considered outside of the mainstream of the then-centrist GOP; serious consideration was given to leaving the GOP and forming a new conservative party in coalition with the "states' rights" Democrats of the South.
Reagan would have been a RINO on the left and Goldwater and Taft would have been RINOs on the radical right.
But even Goldwater was against the "religious right."
“Mark my word, if and when these preachers get control of the [Republican] party, and they're sure trying to do so, it's going to be a terrible [censored] problem. Frankly, these people frighten me. Politics and governing demand compromise. But these Christians believe they are acting in the name of God, so they can't and won't compromise. I know, I've tried to deal with them.” Barry Goldwater.
Regarding being politically involved, Moral Majority founder Jerry Falwell told the news media that "every good Christian should be concerned." Barry Goldwater replied, "Every good Christian should line up and kick Jerry Falwell's [censored]."
President Eisenhower held views on the military industrial complex that were completely un-Republican and said, “Every gun that is made, every warship launched, every rocket fired signifies, in the final sense, a theft from those who hunger and are not fed, those who are cold and are not clothed. This world in arms is not spending money alone. It is spending the sweat of its laborers, the genius of its scientists and the hopes of its children.”
A significant percentage of the Republican Party would not listen to Eisenhower on things such, war and the military, though he was a West Point graduate and the supreme commander of the Allied Forces during World War II.
He wanted to shut down the war profiteers who were funding most of the Republican Party (and still do) and warned us of the dangers of the "Military Industrial Complex," a term he coined when he left office in 1961.
The young NEOCONS don't have a clue about the history of their own party.