The reality series American Idol became a bonafide cultural phenomenon in the early 2000s. Of course, many people tuned in for the experience - finding a talented unknown, voting for them week after week, and watching them ascend through the ranks before becoming a national superstar. Others just liked hearing Simon Cowell's relentless and often-bordering-on-rude put-downs.

RELATED: The 10 First Winners Of American Idol & Their Most Iconic Songs

There's no denying that the judges are an integral part of American Idol's success. Unfortunately, the quality of the judges has often varied wildly throughout the years, resulting in a rather mixed bag of quality.

Best: Simon Cowell

Simon Cowell Waving

There's just no denying that Simon Cowell is the most popular American Idol judge of all time. Being the "best" is certainly up for debate, but Cowell helped make American Idol what it was, and many tuned in solely for him. His insults also made for some of the funniest auditions. Cowell is often regarded as the best judge, both by Reddit users planethorror and Jackson423843.

The latter writes, "I used to think he was unnecessarily critical but now as an adult I realize that that's what you want. I do think he could've showed a bit more empathy at times but at the end of the day he knew what he was talking about and wasn't afraid to tell the contestants."

Worst: Mariah Carey

Mariah Carey on American Idol

Despite being an obvious pop icon, Mariah Carey made for a disappointing American Idol judge in the eyes of some. Her performance even transcended the American Idol subreddit, with her awkward judging even appearing on the r/cringe subreddit.

User Jackson423843 sums it up nicely, writing, "Unlike the Simon and Paula feud, her feud with Nicki was just uncomfortable to watch." There was also the problem of her "scowling and...two word critiques." MarionCotesworthHaye agrees (even despite their personal bias), calling Carey a "useless judge."

Best: Steven Tyler

Steven Tyler leaning towards a mic in American Idol

Aerosmith is a legendary rock band, and their music has appeared in countless movies throughout the years. Hype was high for his judging appearance on American Idol, and he did not disappoint.

He is a favorite among the Reddit community, with user TictacTyler saying, "I liked Steven Tyler the best." lasagnaisgreat57 agrees, stating, " I remember him always being funny, I always liked him." As it turns out, Steven Tyler is not just a great musician, but a great judge as well.

Worst: Katy Perry

lionel richie katy perry ryan seacrest luke bryan on american idol

Katy Perry may have a lot of Instagram followers, but that doesn't make her a great judge. Many Reddit fans have questioned Perry's abilities as a judge, and many don't care for her. Jackson423843 writes, "She tries to make the show all about herself and is very malicious in the auditions."

User BuffaloAmbitious3531 simply states, "I'll pass." And 6-man isn't shy about their beliefs, bluntly writing, "Once she hits the [live shows] she mostly sucks." Good pop music doesn't necessarily make for a good judge.

Best: Harry Connick Jr

Harry Connick Jr singing on American Idol

The response towards Harry Connick Jr is more divisive than outright positive. Many fans admit that he was passionate and knowledgeable, including MoulinSarah ("Harry was the best as far as actual musical critique."), ConwayThrowbury ("Harry was tops for me in giving contestants good musical advice.") and 6-man ("He was inarguably the best judge the show has ever had.").

RELATED: 10 Best American Adaptations Of British TV Shows

But some also conceded that he could be a bit of a jerk, including Jackson423843, who writes, "He may give Simon a run for his money for meanest judge the show has had."

Worst: Kara DioGuardi

The judges of American Idol sitting at a table

There's no denying that Kara DioGuardi is one of the most maligned judges in the history of American Idol. Simply perusing Reddit, it seems as if no one likes her. MoulinSarah is quite hilarious in their criticism, stating, "Everyone else is in a pile at the bottom with Kara underneath."

User 6-man called her "terrible on season 8." And Jackson423843 writes, "She was kind of annoying and didn't seem into the show at all as she promptly left." There are certainly more memorable American Idol judges out there.

Best: Randy Jackson

american idol randy jackson

There's no going wrong with any of the original American Idol judges. They undoubtedly helped make the show a hit, they all proved charismatic in their own way, and they have the ability to strike nostalgia in the hearts of all '90s children.

RELATED: 10 Scenes From American Idol Viewers Love To Rewatch Over And Over

User Jackson423843 loves Randy, stating, "I think him and Simon were really the only two who really knew how to critique the contestants." lasagnaisgreat57 is also a big fan, stating, "Randy was always my favorite. I still remember all his quotes, and I think he was always nice while still giving good criticism."

Worst: Ellen DeGeneres

An image of Ellen DeGeneres sitting on the panel on American Idol

Ellen DeGeneres has certainly faced a lot of criticism and controversy over the last couple of years, but that has nothing to do with her reputation as a poor American Idol judge. No one on Reddit seems to like her. Jackson423843 admits that "she was probably the least knowledgeable," and MarionCotesworthHaye simply writes, "useless."

But perhaps the wildest criticism comes from 6-man, who only states, without elaborating, "no." It seems like the inclusion of DeGeneres was a ratings grab and nothing more.

Best: Nicki Minaj

Nicki Minaj in front of a mic on American Idol

The popular Nicki Minaj could have easily been another pop star brought in to simply draw eyeballs, but she actually proved a very valuable and entertaining judge. Many people were pleasantly surprised by her abilities, with Jackson423843 writing, "She was very well-spoken and seemed to really take her spot on the judging panel seriously which I respect."

User MarionCotesworthHaye agrees stating, "[She] offered a modicum of real talk while the Idol ship was sinking." And finally, BuffaloAmbitious3531 sums her up with a few short words, summarizing "lot of personality, lot of astute criticism."

Worst: Luke Bryan

Judges Lionel Richie, Katy Perry and Luke Bryan on American Idol

One of the biggest country stars of the decade, Luke Bryan has received numerous accolades, three #1 albums, and ten #1 Hot Country singles. Unfortunately, his talents do not carry over into judging. Jackson423843 admits that he's a nice guy but states, "I don't think his place is as a judge."

In fact, most of the criticism stems from his too-kind personality. MarionCotesworthHaye says he "offers no actionable critique," 6-man says he is "usually too kind," and BuffaloAmbitious3531 jokingly states, "I'll form an opinion on how good of a judge he is as soon as he judges something."

NEXT: 10 Best American Idol Auditions From Its Original Run