Definitely Reagan. Nixon signed the EPA into existence and oversaw the final stages of the Apollo program to get us to the moon. He also ended the Vietnam war (after escalating it, but he did end it).
Reagan... gave a speech in front of the Berlin Wall? Said no to drugs? Didn't turn the Earth into a radioactive hellhole? I don't know. I honestly can't think of anything I can give him any credit for as president.
Nixon didn't just escalate Vietnam, he sabotaged Johnson's attempt to end it so that he could run on ending the war. And then he waffled on it after he won the election because he realized it would make him the president that lost the Vietnam war (which is doubly stupid because, at least from my perspective, "lost Vietnam" isn't even a part of his legacy, despite him being one of the least popular presidents in recent history).
Oh yeah, I agree that Reagan was worse. Meant that as a "Nixon was even worse than your wording suggested which makes Reagan look even worse because he still doesn't meet the lowered bar".
unfortunately reagan was in my lifetime. I actually did not get the level of hate nixon had until I experience a few of these presidents combined with the parts of sicko where they played his taped white house conversations. Also I eventually knew someone from chile.
I think the criminal acts that Nixon got busted for put him about Reagan on this one. Of course both of them also passed laws that continue to have devastating effects.