WHO’S TO BLAME for Ashton Kutcher? Look no further than “That ’70s Show,” the Fox comedy that ran from 1998 to 2006, spawned the careers of Kutcher, Mila Kunis and other members of the ensemble cast and helped Fox gain the teen viewers that would later catapult “The O.C.” into instant success.

For eight years, “That ’70s Show” gave a look into the decade of feminism, economic recession, Led Zeppelin and “Star Wars,” providing goofy humor with doses of seriousness and sentimentality (and, of course, the pot-smoking circle).

But things weren’t all giggles for the series. Though it started strong (Eric and Donna were so in love! Laurie was such a skank! Hyde was such a rebellious badass!), things started going downhill when the stars of the show began outgrowing it. Topher Grace (who played main character Eric Forman) and Kutcher (who played loveable dope/womanizer Michael Kelso) decided their careers would be better off without “That ’70s Show,” and so at the end of the seventh season, they were written out — leading into a shockingly boring eighth season that flung all the characters into unbelievable storylines that went against everything the show had developed until that point.

You can zone in on the many good bits of “That ’70s Show” with the new complete DVD giftset of the show. But to save yourself some trouble (and brain cells), Express breaks down the five most unbelievable moments in the show’s final two seasons.

» 5. Jackie and … Fez?
When it comes to girls, Fez (Wilmer Valderrama) is probably the last person any girl would want to date: sexually obsessed to a fault, creepy, somewhat dumb. And yet, Jackie Burkhart (Mila Kunis), the show’s resident babe, moves from Kelso, who can’t stop cheating on her, to Steven Hyde (Danny Masterson), who can’t bring himself to marry her, to Fez, who she thinks (for some reason) has every quality a girl could ask for.

As Kelso describes it, “I think it makes total sense that Fez ended up with Jackie. She started out with me, the Ferrari, and then she went to Hyde, the Mustang, and now she’s with Fez, who’s like a donkey pulling a cart full of brightly colored Mexican blankets.”

Her sudden swing of affection in his direction, even though she admits earlier in the season that she will always love Kelso and Hyde for the major roles they played in her life, seems duplicitous at best, completely false at worst. But if she really wants to get with a guy that is probably more obsessed with candy and pornography than he is with her, then be our guest.

» 4. Eric Goes to Africa
Though Eric is always portrayed as the most morally inclined of the group, never once during the show’s past seasons was it ever suggested that Eric cared more about the outside world than he ever did about himself. An avid “Star Wars” fan, Eric often takes abuse from Red (“dumbass!”), and instead prefers to cater to his mother, Kitty (except for when she started that whole menopause thing), all while staying devoted to his friends (well, when he’s not mocking them relentlessly) or doting on Donna (who wouldn’t?).

But Eric’s development as a character only seemed to take off in the last few seasons — and when it did, it seemed incredibly forced and uninspired. Deciding he wanted to go to college — since when? Choosing to teach in Africa to raise money — who would have thought? Not us.

» 3. The Break-Up
While Jackie and Kelso were on-again, off-again for most of “That ’70s Show,” Eric and Donna’s relationship started off shaky and only grew more strong as the series progressed. Since winning her heart (and beating Hyde in the process), Eric has devoted practically every second to Donna, from supporting her during her radio show stint as “Hot Donna” to defending her against Kitty’s attacks. When he proposed, it seemed like a typical high school romance — but with staying power.

So when he let cold feet get the better of him, stood her up at the wedding rehearsal and eventually left for Africa, the plotline got a little iffy. Add in a weak description of their break-up from Donna — who seems to get over it mighty quick, considering they were supposed to be latched to each other for life and stuff — and season eight was a definite downgrade.

» 4. Randy
Why, oh why, was there a need to replace Eric’s character with one who was infinitely worse? Enter Randy Pearson, portrayed by Josh Meyers as the new guy in the circle and Donna’s latest love interest.

Sure, “That ’70s Show” has had good supporting characters in the past — Luke Wilson was great as Kelso’s older brother, Casey Kelso, and even Jessica Simpson gave a tongue-in-cheek turn as the busty blonde Annette. But Meyers was too bland to work as Randy, and while it was obvious that the show’s creators were trying to use the character as a stand-in for Eric, he was just too shallowly developed to work — and for the sake of all that is good and holy, we’ve got to veto that hair.

» 5. “That ’80s Show”
After the series finale ends and the gang has counted down from 10 to one, marking the crossover from Dec. 31, 1979 to Jan. 1, 1980, the credits roll over a scene of the group years before, singing along with “Hello It’s Me,” by Todd Rundgren, presumably as they come home from the concert they are seen driving to in the beginning credits of the show.

And at the end of that segment, when the Wisconsin license plate pops up on screen, the little numerals on the bottom right corner now read “80,” marking the new decade and creating a sort of segue into the stylistic spin-off, “That ’80s Show.” As miserable as the show was, at least it bombed after only one season — allowing actor Glenn Howerton to move on to slightly bigger but way better things (see: the hilariousness of “It’s Always Sunny in Philadelphia”). For that, we are forever grateful.

Written by Express contributor Roxana Hadadi