30 Rock's main cast might have comprised the lion's share of stories on the show, but they wouldn't have been nearly as successful or hilarious without the stellar supporting cast they had. Sure, Liz and Jack could carry a storyline on their own, and Tracy and Kenneth would often get into trouble with Jenna, but the supporting cast of characters was what made the show really click.
Some of the characters were more important than others, though. Some of the cast members got lost in the shuffle, and they might have been slightly forgotten as the show went on. Still, in its own self-referential way, 30 Rock always made sure to remind people that these characters existed.
Poor, poor Danny. He never really did get much respect on TGS. It might have been because he was a new cast member coming into the show so late, and it might have been because he just wasn't all that interesting.
Danny, who started his life in the entertainment business as a human statue, turns out to be a Canadian transplant in New York. Sure, this makes for some solid jokes about the culture clash between Americans and Canadians, but ultimately, Danny is pretty much forgotten about, a fact that even becomes a line in the show.
Josh was the original Danny, in the sense that he was the TGS cast member that everyone kept forgetting about. Josh might have gotten along with most of the writers and could do a great Tracy Jordan impression, but he never had much of a personality.
Josh was more of a fun character when he was being put through the wringer by other people. This was most clearly demonstrated in the episode where Josh has to renegotiate his contract, and after Jack seems to let him off the hook too easily, Liz orders him to do the worm, and for his agent to do a crab walk.
Is Cerie the secret ingredient that makes TGS run smoothly? Definitely not. She's an attractive young woman who gets way too much attention from the male writers. There's not a lot of character development for her beyond that.
There are a lot of moments where Cerie does get to shine though, mostly to remind Liz how old she is in comparison to the young receptionist. She does also get off some really good unintentional burns here and there. Still, she mostly exists to make the writers crazy and to make Liz feel bad about herself.
Jonathan is Jack's trusty assistant, and he may just be a little too dedicated to his job. He's also completely obsessed with Jack, in a way that makes Jack uncomfortable a lot of the time, but also comes in really handy.
For example, it's very easy to ditch Jonathan by telling him to get croissants from a bakery that doesn't exist. Even though the directions take him to an old taxi garage, he insists that Jack is never fallable, so there must be croissants around there somewhere.
James Spurlock, more commonly referred to by the show's staff as Toofer, got his nickname because by being black and also a Harvard graduate, the show got a two-for-0ne deal. He's definitely the most uptight writer of the group, which makes him a perfect foil for everyone else.
Toofer constantly gets a lot of flack for his intelligence, which at times really does come off as very pompous. He also desperately feels the need to remind everyone that he went to Harvard any chance he gets ("You know, I went to school in Boston. Well, not in Boston, but just outside of it...").
Lutz might just be the most pathetic writer of the bunch. While everyone else seems to have personality traits that could be considered redeeming, Lutz is basically just a giant manchild who is the target of most of the staff's mockery.
John Lutz, who plays Lutz on the show, is a seasoned improv performer, and he must be truly dedicated to his craft to make himself look like such a loser on a regular basis. Still, he got his ultimate revenge in the final episode of the series when he picked Blimpy's for the show's last lunch.
For most of 30 Rock's run, it seemed like Jenna Maroney would never really find love. After all, who could ever love Jenna as much as she loves herself? Eventually, though, she stumbled upon drag performer Paul (Will Forte) whose specialty was playing Jenna in his drag show.
Needless to say, the two fell for each other hard, and their very strange ideas of what constitutes a healthy relationship made them the perfect match. Paul might have been an odd guy, but he was always very sweet and down-to-Earth, even when suggesting the weirdest things he and Jenna could do in the bedroom.
3 Dennis Duffy
"You'll be back, Lemon!" That was the call of perpetual loser Dennis Duffy, a man so disconnected from reality that he thought a lucrative business was owning a coffee vending machine in the basement of a K-Mart.
Played with the perfect amount of knuckleheadedness by Dean Winters, Dennis was the man that Liz just couldn't get out of her life, despite all of her efforts. Dennis is the kind of guy who would build shelves for Liz's TV, then appear on an episode of To Catch A Predator as soon as Liz turned it on.
2 Grizz and Dot Com
Of all the supporting characters on the show, none offer more support, really, than Grizz and Dot Com (played by Grizz Chapman and Kevin Brown, respectively). These two burly members of Tracy Jordan's entourage (and really, they're the only members) look tough, but they're actually just two big sweethearts.
Grizz and Dot Com are both the most well-spoken characters on the show, and even though they are often given short shrift by the other characters, mostly Tracy, they remain confident and supportive of each other.
1 Dr. Leo Spaceman
Who else would take the top spot on a list of supporting 30 Rock characters than Leo Spaceman himself? Played as a perfect blend of straight man and goofball by Chris Parnell, Dr. Spaceman (pronounced Spa-chemen), was always on hand as the show's resident medical professional.
The only problem is that Dr. Spaceman's qualifications were highly dubious. He never really seemed to know anything about medicine, including the correct pronunciation of 'diabetes.' He was also grossed out by giving people needles, which seems like it would be a normal part of his job. However, he was always around to give Jenna medical advice, like losing weight with meth.