Many of the more recent Milestone Celebrations, where most of the departed anchors (such as Tom Brokaw and Barbara Walters), except for those few who are no longer around (e.g. Dave Garroway), return to the show to celebrate with the current anchors. Also a Heartwarming Moment; it just gives off a feeling of wholeness to see all these people together, old and new.
Willard Scott's epic Carmen Miranda impression during his first few years on the show. It completely won him over on a national level (prior to Today he was mostly known only in the Washington DC area) and cemented his Ensemble Darkhorse status, a status he would retain all throughout The Eighties and well into The Nineties (he's still on the show to this day, doing the Smucker's 100th birthdays segment).
Really, as mentioned above, the very fact that Willard is still on the show, even after Bryant Gumbel's scathing memo got leaked, after his beloved wife passed away, after suffering a panic attack when about to do the weather. He handled all of that gracefully, and while his role on the show has considerably decreased, he remains an inspiration (not to mention a dear friend) to the entire Today team.