One of the happier surprises of this TV season has been my deepening crush on Grey's Anatomy, which has taken advantage of Desperate Housewives' sophomore malaise to become the water-cooler show on Sunday night. (And a show I gave a lukewarm review when it premiered last spring.)

This week's (Oct. 30) episode may have been the best yet, a scintillating mix of soap opera and medical drama — with just the right blend of mordant comedy (Cristina's hunt for the missing leg) and wrenching tragedy (the two train passengers impaled by a metal pole, only one of whom could possibly survive).

Grey's is a fabulous show for "shippers" who groove on will-they-or-won't-they dynamics, epitomized by Meredith's mortifyingly drunken wait for Dr. McDreamy's answer — will he pick her, as she asked him to do to his face, or will he stay with his intimidating estranged wife Addison (a name I've loved since All About Eve). He picked Addison, but for how long?

Ellen Pompeo and Patrick Dempsey are perfectly sympathetic and swoony as the star-crossed couple, but there's also the compellingly tentative relationship between another young doctor and her aloof boss, with Sandra Oh's voraciously ambitious Cristina Yang battling her feelings for Isaiah Washington's coolly efficient Dr. Burke.

Adding new wrinkles to the show's relationship romp is the Izzie-Alex flirtation, nicely underplayed by Katherine Heigl and Justin Chambers. Izzie is justifiably puzzled over obnoxious hotdog Alex's sudden ambivalence toward his work and his play. (He didn't even kiss the former underwear model on their date.) How long before everyone realizes that Alex's medical career is in the balance?

And then there's my absolute favorite, George (T.R. Knight), a mouse who roars when the circumstances are right. He stepped up like a champ when he and Alex were stuck in a stalled elevator with a patient who needed emergency open-heart surgery. (Alex, struggling with self-doubt, froze.) At home with Meredith and Izzie, George is treated like one of the girls, with the condescension you'd give a tagalong brother or maybe a pet. He writhes with comic frustration at not being taken seriously, as either a doctor or a man. But we can see what they don't, that he's got the goods.

The other great performance on Grey's Anatomy is Chandra Wilson's brusque, funny and ferocious Dr. Bailey, supervisor of the young docs. A tiny dynamo of attitude and barely disguised compassion, she's a role model in many ways, not the least being the fact (which came as a surprise to all) that she has been happily married for years.

Grey's Anatomy has charisma and tremendous entertainment value and buzzes with the glorious hum of all cylinders working, reminiscent of ER during its early days. (That original cast is taking on a mythic hue, kind of like Saturday Night Live's classic ensemble of the first five years.) Though ER has badly faded into a mopey bad habit occasionally brought to life by a memorable patient, Grey's and House (which makes a welcome return this week) prove that the TV medical drama is far from dead.