Chris Noth on Last Season of 'Sex,' 'L&O'

June 19 -- — Chris Noth waxed a little sentimental as Sex and the City kicks off its final season, and while he still respects his old show, Law & Order, he thinks the landmark cop show has become "watered-down" and "tired."

Noth, who plays Mr. Big, Sarah Jessica Parker's on-again, off-again boyfriend, says it's good that Sex is ending while the show is still fresh.

"I think Sarah and all the girls are right," the actor told ABCNEWS Radio. "We've done it. There's no more to do. We've covered the ground and it's better to leave them thinking about it and leave some mystery."

Noth, 48, became a familiar face to TV viewers as the hotheaded Detective Mike Logan on Law & Order. He was with the NBC drama from 1990 to 1995 before joining Sex and the City as the commitment-phobic financier who alternatively romances and disappoints Parker's Carrie Bradshaw.

"I was with the original [Law & Order] pilot and the original cast and I think it's kind of watered-down now, frankly … I don't mean to be negative about it," he said. "That's why I'm glad Sex and the City is only doing six seasons."

Marriage, Arrests … And Mr. Big’s First Name

At the New York City premiere party kicking off the HBO comedy's last season, Noth joined Parker and her on-screen gal-pals Kristin Davis, Kim Cattrall and Cynthia Nixon, as well as other stars, including Jamie-Lynn Sigler of The Sopranos and talk show host Caroline Rhea.

The cast was mostly tight-lipped about what fate holds for Carrie and her posse. According to the scuttlebutt, one of the ladies will marry, one will get arrested and another will get a "Dear John" letter via a Post-it Note. Several ex-boyfriends, including Noth, will be returning, keeping fans guessing who gets what.

The season begins Sunday at 9 p.m. Eastern Time with the first of 20 episodes. Twelve will run through the summer and another eight will air beginning in January.

Nixon, who plays the sarcastic lawyer Miranda, suggests there may be a big turn in her relationship with Steve, the bartender who fathered her character's child.