There are so many great sitcoms, both old and new, that feature families at the heart of their stories. And within those families are often siblings. Sometimes, the siblings get along. But oftentimes, there's a rivalry of some kind going on. It might be serious, fueled by deep trauma, or hilariously innocent and all for fun and games.

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So which have been the best sibling rivalries in sitcoms from the 2000s? Here are some picks.

DJ And Stephanie Tanner: Fuller House (2016)

fuller house dj and stephanie staring at each other

Premiering in 2016 and streaming for five seasons, this sequel to the '80s and '90s sitcom Full House saw DJ and Stephanie resume their sibling rivalry, despite both being grown adults.

DJ remained the Type A, upbeat woman who did everything right while Stephanie resented her seemingly picture-perfect sister and jumped at any chance she could to beat her at something, anything. Their claws really came out in the newlywed game show episode of Fuller House when the kids tried to pit the sisters (and Kimmy) against one another to see who knew the most about their fiancé.

Lisa And Bart Simpson: The Simpsons

Matt Groening Bart and Lisa Simpson

As the longest-running American sitcom, eldest kids Bart and Lisa.

Bart is the typical mischievous boy while Lisa is the overachieving bookworm. And while they usually have one another's backs when needed, they also bicker like, well, brother and sister.

Haley And Alex Dunphy: Modern Family

Haley was the typical pretty and popular girl who was more interested in boys and parties than school. She grew into an equally aimless young adult who had to work hard to find her footing. Alex, meanwhile, was the uptight, overachieving, highly sarcastic younger sister who seemingly loathed her egotistical sister.

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Deep down, they showed they cared for one another. But the rivalry on constantly traded insults, with Haley making fun of Alex's lack of social life and Alex mocking Haley's dimwittedness.

Phoebe And Ursula Buffay: Friends

Phoebe talks to Ursula in Friends.

While Ursula was only featured in a few episodes of Friends, the two had a rivalry that started early on in their childhoods when, after a series of unfortunate events with their real and then adoptive parents, Ursula was taken into care while Phoebe ended up on the streets.

Ursula was selfish and constantly insulted Phoebe, who was jealous that her sister had been viewed as the "better" twin and given a better life while Phoebe was left to fend for herself. Both characters were played by Lisa Kudrow.

Michael And Gob Bluth: Arrested Development

Will Arnett as Gob and Jason Bateman as Michael in Arrested Development

The second-oldest Bluth son on Arrested Development, Michael, was the only "normal" one who was tasked with keeping the dysfunctional family together. But the eldest child, George Oscar Bluth, otherwise known as "Gob," tended to get under his skin.

Michael was the more successful brother and considered the "golden child" while Gob believed that, as the eldest, he deserved more respect. The two eventually realized that their own parents had manipulated and encouraged the rivalry. Nonetheless, despite having deep respect and love for one another, they couldn't help but compete.

Becky And Darlene Conner: The Conners

Becky adult learning

Since back on the original series, Roseanne, Becky, and Darlene have been very different people. Becky was the hard-partying teenager who skipped school, spent time with her boyfriend, and didn't have many life goals. Darlene was the darker, more goth-like teen who kept to herself and spewed insults any time she got the chance.

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They are always there for one another but the rivalry continues in The Conners as they take every opportunity to poke at each other's flaws, including Becky's promiscuity and Darlene's failed marriage.

Charlie And Alan Harper: Two and a Half Men

Charlie was the forever playboy, a successful jingle writer who lived a free-spirited and promiscuous life in a beach house. Alan, meanwhile, was in an unhappy marriage and was eventually kicked out with his young son, with nowhere to go.

While Charlie reluctantly took his brother in, which set the stage for Charlie's success in life, and especially with women.

Dr. Frasier Crane and Dr. Niles Crane: Frasier

Airing from the early '90s all the way through to the '00s, Frasier and Niles had an interesting rivalry on Frasier in that they were both grown adult men who were highly intelligent and refined. Yet brothers will be brothers and they still had their issues and could act like teenagers now and again.

Their equally expensive tastes and inflated egos meant they were bound to butt heads and disagree on things. The ironic thing about it was that both worked in the field of psychiatry yet couldn't seem to resolve their own issues when it came to feelings towards the other.

Malcolm, Reese, and Dewey: Malcolm in the Middle

The family  in Malcolm in the Middle standing next to each other

Frankie was the highly intelligent, genius-level middle son on Malcolm in the Middle who was stuck dealing with his dysfunctional family, which included his four brothers. He was closest in age, however, to Reese and Dewey.

Reese was the "cooler" older brother while Dewey was the nerdy younger one that the boys tended to manipulate and make fun of. Malcolm often found himself being the butt of Reese's jokes and the subject of his constant torments. As a dimwitted bully, Reese dealt with his feelings of inadequacy by making fun of Malcolm's superior intelligence.

Raymond and Robert Barone: Everybody Loves Raymond

Robert Barone and Gianni in Everybody Loves Raymond

At the crux of their rivalry was the fact that Raymond was clearly the favorite son of the two brothers, the successful sportswriter who was the apple of his mothers' eye. Robert, meanwhile, was a police officer who still lived at home with his parents, had no prospects of love, and was generally miserable.

Robert was clearly jealous of his younger bro on Everybody Loves Raymond, which caused the two to argue like children and constantly compete with one another on meaningless things.

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