By Ken Tucker
Updated March 23, 2007 at 04:00 AM EDT

It’s not like I don’t understand why CSI is considered an uncool show by people who otherwise share my taste in TV — you bet I’m hooked on Heroes and Battlestar Galactica — but I also realize that, after seven seasons, CSI is middle-aged when measured in TV-cool years. No one can look at that thickness around my man William Petersen’s neck and think he’s as happenin’ as, say, America Ferrera, but that only means hipness is overrated.

And I also get why CSI has recently been ratings-dinged by Grey’s Anatomy: Shiny soap opera trumps dark procedural any day of the week, and in an American Idol world, characters deploying cold logic will always be at a disadvantage over real humans making hot messes of themselves.

But that doesn’t stop me from crowing that this is probably the best, most enjoyable season of CSI ever. The story arc that could have proved gimmicky — the ”miniature killer,” who makes tiny, meticulous reproductions of his crime scenes — is instead chillingly funny (one of his victims was Danny Bonaduce, and who hasn’t wanted to see that jabbering reality train wreck literally reduced to a silent, tiny body?), and it furthers our knowledge of Petersen’s Gil Grissom. You just knew that the fussy, meticulous Grissom would get really jazzed by a criminal whose mind works eerily like his own.

And CSI‘s potential momentum killer — Petersen exiting for a few episodes to go do a play — proved a gas, as Liev Schreiber arrived in Vegas as Mike Keppler, a New Jersey CSI with more skeletons in his closet than a Halloween-costume salesman. If anything, Keppler was even more shut down and mysterious than Grissom, which only added to the former’s allure. Marg Helgenberger’s hard-bitten Catherine fell for the guy, and when Keppler died (oh, gee: post-spoiler alert!), one inventive YouTuber put up a Keppler montage that concludes with the text: ”A Keppler Lover to the End…By Lover, I Mean I Wanted to Have Sex With Him.”

No one does heroes like CSI. Indeed, uninteresting lead guys are one reason the spin-offs don’t work for me. Glaring CSI: Miami wins its time period, but David Caruso is self-parodying — Conan O’Brien with a sunglasses OCD — while over on drab CSI: NY, Gary Sinise’s pained silences seem like mute cries for a contract release.

An upcoming edition, airing March 29, breaks the usual two-case-per-show formula. It shows how the entire CSI crew is emotionally affected by a particularly gruesome multiple murder. That would signal ”very special drippy episode,” but CSI demonstrates that you can deal with a softer, muted tone without going limp.

Yep: The Who may still coo ”Who are you?” as theme music, but CSI knows exactly what it is. A-