Climaxing a season of swelling anticipation, Ellen Morgan (the bookstore-managing alter ego of Ellen DeGeneres) finally acknowledges her lesbianism tonight in an “Ellen” hour that represents television’s most hyped coming out since Little Ricky came out of Lucy 44 years ago.

For that reason alone, it’s easy to go into the segment dubbed “The Puppy Episode” wanting to hate it. The enormous buildup (DeGeneres uncloseting herself on the cover of Time magazine, thinkpieces in the New York Times, endless speculation) has made this “Must-See TV” event appear doomed to cloying anticlimax.

It is a tribute to all involved that it isn’t. Instead, the episode is undoubtedly the funniest and most moving in the sitcom’s four years on the air thanks to a script (from Mark Driscoll, Dava Savel, Tracy Newman and Jonathan Stark) that steers clear of the typical heavy-handed messages and speechifying. What it substitutes is laughs. Genuine ones. And lots of them.

This is a minor miracle, considering the pressure on this episode to carry the torch for a new open-mindedness in primetime. DeGeneres’ character is, after all, the first series lead to openly identify herself as gay. As if that weren’t enough, the Touchstone TV series further called attention to itself with stunt casting up the proverbial wazoo.

And yet director Gil Junger and what may be the largest producer list in comedy series history (13 in all) refuse to cave in to the temptation to transform the hour into a crusade. They don’t take jabs at the religious right or climb onto any politically correct soapboxes, nor do they play being gay as a lifestyle all should be encouraged to adopt.

Instead, “Ellen” takes the subject of a young woman’s sexual denial, confusion and ultimate acceptance and uses it as fodder for pointed humor — rightly deciding that the best way for a sitcom to address something seriously is to not take it that seriously at all.

As the show opens, Ellen meets an openly gay news producer named Susan (Laura Dern) and suddenly senses an attraction stirring. Repulsed, she pushes those feelings down and goes out with old squeeze Richard (Steven Eckholdt), who puts moves on Ellen that leave her uncomfortable and perplexed.

To mask the inevitable, Ellen tells her bookstore pals that she and Richard went at it in his hotel room like dogs in heat (“I guess I’m just a sucker for man-woman sex”).

Ellen begins coming to terms with the fact that her feelings for Susan may be more than a passing fancy and attempts with much angst to explore them with her therapist, Oprah Winfrey (we can only imagine how much she might charge for 50 minutes).

When Ellen finally tells Susan she is gay, after much hemming and hawing, she inadvertently blurts the word into an airport microphone. It’s a magical comic moment.

An uproarious dream sequence showing a bewildered Ellen in the supermarket sports an endless sea of star cameos, including Billy Bob Thornton telling her they “have a special this week for lesbians” wanting to buy melon, k.d. lang working as a checker in the ‘ 10 lesbians or less” aisle and Demi Moore and Dwight Yoakam also popping up.

One of the perils of working in front of a live audience is that every time there is any allusion to Ellen’s gay feelings, the line is punctuated with a maturity-challenged “Woooooooh!!!!” from the crowd. It ends up blunting the impact a tad.

As the hour winds down, Ellen faces the prospect of breaking the gay news to her friends. But it creates none of the disapproving reactions that would turn this into an issue-driven hour carrying an agenda.

One can certainly quibble, however, with the decision to keep “The Puppy Episode” so safe and pristine. Ellen and Susan hug, but they never come close to kissing or otherwise touching. And of course, it’s difficult to believe that a 35-year-old woman would suddenly acknowledge lesbian feelings only after chatting with Laura Dern.

Also, it’s a mite disappointing – although surely not surprising – that ABC would use the very private issue of a woman’s sexuality (of both DeGeneres and her character) as just another sweeps ratings device.

This is not, however, to at all minimize the importance of the episode or of DeGeneres’ guts in agreeing to make it. If she is indeed committing career suicide, the woman is certainly going out in style.