A modest site, with amazing content: http://www.hpol.org/. Audiotapes of luminaries from FDR to Clinton, including, of course, Nixon's extended conversation with Haldeman/Ehrlichman about the Watergate breakin, with a running transcript to assist. Even more illuminating is a series of phonecalls LBJ made in 1964, agonizing with advisors and friends (anyone who would listen) over the decision to increase the military commitment in VietNam. It's important to hear, especially for us old Johnson-haters. The man really was tormented over his options and he got precious little help from those he consulted. Whatever I thought of LBJ, I know now he's not at all the madman who now occupies the White House -- Mr. "Bring 'em on!"-- who pumped his fist, saying "Feels good," moments before he announced to the nation that he was ordering the invasion of Iraq.
And, for fun, you can listen to a cut of a tape of Clinton denying sex with various ladies.