Answer by taking a quote from the following article:

Rowan & Martin's Laugh-In (often simply referred to as Laugh-In) is an American sketch comedy television program that ran for 140 episodes from January 22, 1968, to March 12, 1973, on the NBC television network. It was hosted by comedians Dan Rowan and Dick Martin. Laugh-In originally aired as a one-time special on September 9, 1967, and was such a success that it was brought back as a series, replacing The Man from U.N.C.L.E. on Mondays at 8 pm (ET). The title of the show was a play on the "love-ins" or "be-ins" of the 1960s hippie culture, terms that were, in turn, derived from "sit-ins", common in protests associated with civil rights and antiwar demonstrations of the time.

The first season featured some of the first music videos seen on network TV, with cast members appearing in films set to the music of the Nitty Gritty Dirt Band, the Bee Gees, the Temptations, the Strawberry Alarm Clock, and the First Edition.  During the September 16, 1968, episode, Richard Nixon, running for president, appeared for a few seconds with a disbelieving vocal inflection, asking "Sock it to me?" Nixon was not doused or assaulted. An invitation was extended to Nixon's opponent, Vice President Hubert Humphrey, but he declined. According to George Schlatter, the show's creator, "Humphrey later said that not doing it may have cost him the election", and "[Nixon] said the rest of his life that appearing on Laugh-In is what got him elected. And I believe that. And I've had to live with that." In an episode of the ill-fated 1977 revival, a Nixon impersonator says "I invited the American people to sock-it-to-me.... you can stop now".  On multiple occasions, producer George Schlatter attempted to get William F. Buckley Jr. to appear on the show, only to be refused each time until he suddenly agreed to an appearance. In the episode that aired December 28, 1970, Buckley appeared in an unusual sit-down segment (portions of which were scattered throughout the episode) flanked by Rowan and Martin and fielding questions from the cast (which included Lily Tomlin doing her Fast Talker shtick) and giving humorous answers to each. Near the end, when Rowan asked Buckley why he finally agreed to appear on the show, Buckley explained that Schlatter had written him "an irresistable letter" in which he promised to fly Buckley out to California "in an airplane with two right wings". At the end, Rowan thanked him for appearing, noting that "you can't be that smart without having a sense of humor, and you have a delightful one".

What were some memorable moments?
Richard Nixon, running for president, appeared for a few seconds with a disbelieving vocal inflection, asking "Sock it to me?"