DaveWatch: Countdown to Letterman's Last 'Late Show,' Day 12

Reese Witherspoon gets embarrassed and Dave reminds us why he's irreplaceable as we hit the two-week-til-farewell mark

Reese Witherspoon on 'Late Show with David Letterman.'

Last night's Late Show featured some big-name guests, but most importantly, it found Dave in a feisty mood, bobbing and weaving with refreshing impishness. Maybe it's because he didn't have anyone as significant as the President of the United States on, or maybe he was just feeling particularly ornery. Whatever the reason, it offered up the sort of delights best appreciated by longtime fans. Forget the set pieces, the Top 10 lists, the one-liners and the clip reels: We love the show because we love him — and the more we can get of pure, uncut Dave, the better.

During a predictably rough opening monologue that the host apparently wanted to get through as quickly as possible, he did take a moment after a bit entitled "John Boehner: News You Can Use" to linger over a wonderfully childish clip where the Speaker of the House was looped saying the word "boner" over and over again. Elevating the sophomoric into something resembling smart-ass poetry has been Letterman's gift for decades, and even as he prepares to ride off into the sunset, he's still milking every cheap gag for all the laughs he can squeeze out of it. His small, quiet, deeply pleased smile after running the "boner" clip was his version of a mic drop.

Comfortably loosened up, he soon turned his attention to his guest, Reese Witherspoon. For those coping with the relentless passage of time now that Letterman is retiring, it might have been shocking when Dave brought out a recent photo of Witherspoon with her 15-year-old daughter; the actress, 39, looked almos same age as her girl in the picture. But when the Oscar-winner mentioned that she gave birth the same year that she first appeared on Late Show, Dave mischievously jumped on the comment, theatrically coughing with faux-guilt and saying nervously, "Well, that's an interesting coincidence…" It took Witherspoon a second to get the host's innuendo; her eventual realization and slight embarrassment (matched by the host's feigned ignorance of what he'd said) turned a potentially off-color moment into an adorable one. Dave may be a hopelessly dirty old man, but he's our hopelessly dirty old man.

The rest of the night continued with Letterman painting in the margins, letting his guests peddle their products or sing his praises without getting in their way. Nathan Lane was the evening's designated end-of-an-era M.C., pummeling Dave with one groan-worthy punch line after another. (In the new Avengers, Lane quipped, "I play the Incredible Hulk's second cousin, the Incredible Bulk. Whenever he gets angry, he turns into a large Costco outlet...it was a small part, but it was worth it just to get a look at Thor's hammer." Ba-dump-bump!) The host simply sat back and waited for his moment, finally turning to the camera when his guest paused for a breath to sarcastically repeat, "You got a look at Thor's hammer." It was the best laugh of the interview.

Faced with only a handful of shows left, some hosts might feel panicky about needing to pull out every stop. Last night, Dave demonstrated why his less-is-more attitude has served him well over the years. When Letterman was first doing Late Night in the early 1980s, his ironic, subversive deadpan streak was his weapon of choice — he made not caring (or at least appearing to not give a shit) seem cool. Now comfortably ensconced as a living legend, the man does get lazy on occasion, but he can also retain that sense of hip detachment, suggesting a man confident in the belief that he has nothing left to prove.

That quality came through for just a second during Mumford & Sons' performance of "Believe." Though the cameras were normally trained on frontman Marcus Mumford and his band mates, one quick cutaway revealed Letterman pacing calmly as he cooled his heels in the background. The shot lasted maybe a couple seconds, but it was quintessential elder-statesman Dave: serene, requiring no killer punch lines, completely in his element. Even in the shadows, he commanded your attention. And he wasn't even doing anything. My god, we're going to miss him.