Maybe start with the president?
I did not have sexual relations with that woman - Clinton
We found the weapons of mass destruction. - G.W. Bush
If you like your healthcare plan, you can keep it. - Obama
George H.W. Bush broke a promise, which is not (always) lying. Bill Clinton lied. George W. Bush, it's still not clear, but more likely lying than not. Barack Obama made a promise it turned out was out of his control to keep.
The only one of the four we can say for certain lied is Clinton. And, of course, the current president.
I believe this strict definition comes from being a highly Christian culture where certain sex acts are proscribed and others aren't. "Sexual relations" is really defined as "the sex stuff the Bible says you can't do outside of marriage."
Of course, at a high level, Clinton was very clearly trying to obscure the facts of his relationship with Lewinsky, but whether or not that sentence was literally a lie depends on the definition of the words in the sentence and there is a reasonable interpretation (Clinton himself is from the South) under which it is factually true.
I did not have sexual relations with that woman - Clinton This was a lie.
We found the weapons of mass destruction. - G.W. Bush Some people lied, I'm not entirely sure it was G.W. Bush.
If you like your healthcare plan, you can keep it. - Obama I don't think this was an intentional lie, but an overly broad statement.