Friends mostly follows the lives of the six main group members. However, to keep things exciting, the main cast had to interact with other friends, co-workers, romantic interests, and family members. While viewers excitedly tuned in to watch their favorite six characters in kooky situations for ten years, some supporting characters deserved more screen time than they were given during the series' run. As there were already so many main characters, the focus did not deviate from them often to allow some of the show's recurring cast the opportunity to make a larger impression or appear more often.
JANICE
Janice appeared multiple times a season, and while she may not have made the main characters happy, viewers were always delighted to see her. Janice had a habit of shaking things up and bringing in an extra splash of comedy and insanity to the show. As an exuberant character, there was no one else like Janice in the series. Although she did appear regularly throughout the ten seasons, there were not moments where Janice felt like an unnecessary addition to an episode. Instead, she was an entertaining character to have around and should have gotten more time on the show.
FRANK BUFFAY JR.
Phoebe's family problems were immense, but among all the drama, one relative stood out and made her life brighter. Frank Buffay Jr. comes into Phoebe's presence in the second season and then remains a recurring character going forward. While they don't have the most typical relationship, Phoebe and Frank are there for each other in a way that neither of them claimed to have experienced with other relatives. Frank could be a little over-enthusiastic about things sometimes, but it was easy to see he wanted to have a good relationship with Phoebe, Alice, and the triplets.
DAVID THE SCIENTIST GUY
Only appearing in five episodes during the series' ten-year run, David's appearances are few and far between. While he is the first man Phoebe is serious about, David leaves for Minsk quickly after his introduction. In his time away, Phoebe has many other relationships and does not look as if she misses David, which is justified given the little amount of time they spend together. However, whenever David arrives in New York, the show tries to pull off that Phoebe and David had a strong, undeniable connection. Maybe that would have worked out better had David spent more time on the show. Unfortunately, his lack of appearances makes it difficult to root for him and Phoebe to be together.
CHARLIE WHEELER
Although Charlie first appeared as Ross' colleague, she quickly sparked a relationship with Joey. Being the catalyst for an awkward love square was only part of Charlie's role on the show. She was a rare character on Friends given that could match or be above Ross' intellect while also being interesting in her own right. Unfortunately, her time came to an abrupt end in "The One With Ross' Grant." After reconnecting with an ex-boyfriend to help Ross receive a grant, Charlie and Benjamin realize their feelings have not gone away. Charlie had plenty of potential to grow as a character even if she continued as a colleague rather than a romantic interest for Ross or Joey.
JULIE
Other than showing up at the worst possible moment for the beginning of a potential romance between Ross and Rachel, there was never anything bad about Julie's arrival on the show. She was a sweet woman who was happy to spend time with Ross' friends and was interested in a future with him. Unfortunately, she gets written off mainly as an inconvenience and obstacle to what felt like the inevitable moment Ross and Rachel would get together. Julie had the potential to be a more rounded character than who she was based on the amount of screen time she got.
CAROL AND SUSAN
Similar to Ben, Carol and Susan disappear from Friends in its last few seasons. Contrary to the number of jokes about them, Carol and Susan may have one of the most touching relationships on the series. Even though Carol and Susan were not around often enough to be main characters, they were still relevant to Ross' part of the story. As the parents of Ben, Carol, and Susan had many openings to share storylines regarding Ben growing up and how to raise him. Instead, they fall behind with no explanation.
EMILY WALTHAM
A whirlwind romance between Ross and Emily leads them to a wedding in London. While dating, Emily is a happy and understanding woman as she and Ross grow their relationship. Although fans may not have been rooting for Ross and Emily as a couple, Emily was a nice enough person and excited about marrying Ross. Everything changes when Ross says Rachel's name at the altar. Afterward, Emily's anger and embarrassment are justified, but her possessiveness and ultimatums toward him later are not. As if to make Ross the victim of his own mistake, the show turns Emily into the paranoid villain of the story. This does not match her previous personality going into the marriage, and she deserved more time to handle her feelings and deal with Ross in other ways.
BEN
Ben was a massive deal while Carol was pregnant with him. He was also relevant during the first few seasons of the show to watch Ross bond with his son over life milestones and holiday celebrations. This made Ben's disappearance from the show even more confusing as for someone so relevant in Ross' life, he seems to be written off without a trace. While there are references to Ben in the last two seasons, he does not appear. The reasons are never explained as to where he went or why he was not spending time with Ross.
KATHY
Chandler is struck by horror the moment he realizes that the woman he seriously likes is dating his best friend. Although Chandler feels awful about his feelings for Kathy behind Joey's back, he can not shake his sentiments. Chandler and Kathy take things to the next level after Kathy has broken up with Joey, and he has given his blessing. However, they don't last long together. Taking a page from Ross' book, Chandler becomes paranoid and possessive of Kathy when he believes something is brewing between her and a co-star in a play. As much as Chandler wants to trust her, he can't, and his confrontation of Kathy, declaring that she is cheating on him, is what breaks them up.
URSULA
Lisa Kudrow initially appeared on Mad About You. However, rather than ignore Kudrow's appearance in Mad About You, Friends incorporated Ursula into the show as Phoebe's estranged twin sister. Ursula appeared various times until the eighth season. Everything from her uncaring attitude to her humor balanced Phoebe's whimsy persona. Ursula was a substantial addition to the supporting cast, and her actions could be more surprising than Phoebe's at times. Although she was briefly mentioned in episodes after being written off, Ursula was a fun character to have around, especially for someone considered to be a villain.