If you mean strictly policy wise, Bill Clinton. He balanced the budget and his economic policies contributed to prosperity that his successors took advantage of.
This, by and large. He did, however, sign the repeal of Glass-Steagall, which contributed to the 2008 financial collapse. He was better on social issues, although Obama was better behaved on a personal level.
Clinton was a weasel on NAFTA. During the 1992 campaign, Bush 41 came out squarely for it, while Perot was unalterably opposed. Clinton weaseled about his position, but when he came into office he signed NAFTA and got it ratified, largely because he wanted an accomplishment on his record.
Neither was a BAD President. Both of them have been less than stellar ex-Presidents. I suppose we can't all be Jimmy Carter.
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