These three future TV stars -- Courteney Cox, Teri Hatcher and Mariska Hargitay -- made early guest appearances on Seinfeld. WireImages (3)

A memorable guest spot on Seinfeld has helped launch many an acting career while simultaneously wasting significant chunks of my life -- as well as, judging by our mail, the lives of many 10 Spot readers. Herewith follows our top 10 list of Seinfeld guest spots made before the actors became famous. We're no longer calling them "cameos" because, as Brad Nathan of Los Angeles correctly (if impolitely) pointed out, "Hey fool ... it's not called a 'cameo' if the actor/actress isn't famous yet." So now, without further ado, our favorite before-they-were-famous Seinfeld guest spots:

1. Teri Hatcher as Jerry's girlfriend Sidra
Hatcher barely qualifies for this list because her turn in 1993's "The Implant" episode came just months before the premiere of her series Lois & Clark. Still, her "spectacular" guest turn was by far the most often cited by readers as their favorite. Before displaying her assets as Sidra, Hatcher's biggest acting gig was a six-episode arc on MacGyver, in which MacGyver used a tooth pick, baling wire and a paper clip to determine if her breasts were real. At least, he should have.

2. Mariska Hargitay as Melissa Shannon
Blink and you might have missed her, thanks to an angry George. In '93's "The Pilot," Law & Order: SVU's Hargitay played an actress auditioning for the role of Elaine on the show-within-the-show. Intrigued by Hargitay's looks, Jerry agrees to read for the role with her. But George cuts the scene off quickly, upset that Melissa had entered the room by noting all the actors waiting outside to portray George with the comment, "It's like a bald convention out there!"

3. Megan Mullally as George's girlfriend Betsy
While nearly everyone recalls "The Implant" for Hatcher's chest, few recall the same episode as the lone guest appearance of Will & Grace's Karen. Maybe that's because Mullally didn't speak like she'd just sucked down helium. Instead, she's the rather meek girlfriend whom George accompanies home for the funeral of her Aunt Clarice. That's where George infamously double-dips a chip, which doesn't escape the watchful eye of Betsy's brother, Timmy. I must confess, I had never realized that Betsy was played by Mullally until readers pointed it out. Indeed, if I can learn just one Seinfeld tidbit, then writing this column four days a week is worth it (at least for me).

4. Michael Chiklis as Steve Pocatillo
In '91's "The Stranded," a surprisingly hirsute Chiklis played a man who hosted a party on Long Island that Jerry and Elaine become stranded at when Kramer gets lost while picking them up. Later, Steve visits a reluctant Jerry in Manhattan and proceeds to get drunk with Kramer before calling (but refusing to pay for) a prostitute. Chiklis's career wouldn't really take off, of course, until he started shaving his head as The Shield's Det. Vic Mackey.

5. Jennifer Coolidge as Jerry's girlfriend Jody
Her role as Jody in '93's "The Masseuse" is actually the first listed credit on imdb.com for Coolidge, far better known as Stifler's mom from the American Pie series. In the episode, Jody is the masseuse of the title who frustrates Jerry by refusing to give him a massage. George also falls for her because, "She just dislikes me so much ... It's irresistible."