Party Down should have had an utterly forgettable existence. A quirky-yet-clever comedy about burnout actors passing time as cater waiters that lasted two seasons on a subscription cable network that had next to no track record with original programming, the show somehow found a devoted but small fanbase that has kept its memory alive five years after its unfortunate end.

What is it about the show that has allowed it to resonate? The creative team (John Enbom, Rob Thomas, Dan Etheridge, and Paul Rudd) and the cast (filled with future stars Jane Lynch, Adam Scott, and Lizzy Caplan) deserve the bulk of the credit, Party Down‘s guest star roster also deserves praise. Often there as a favor to executive producer and Veronica Mars creator Rob Thomas (who is celebrating his 50th birthday today), practically every guest star blended in seamlessly with the cast, allowing for some of the show’s best moments. With that in mind, here are some (not all) of the best guest stars from Party Down‘s brief but beloved run.

Kristen Bell (Uda Bengt)

Less a guest star and more a recurring character, Veronica Mars herself played Uda Bengt, the ruthless leader of Party Down‘s main rival, Valhalla Catering. Despite only appearing in a handful of episodes, Bell was able to bring a real personality to Bengt, who became layered once she started dating the show’s protagonist, Adam Scott’s Henry Pollard. Uda developed into a practical, no-nonsense character, instead of the completely scary, completely tiny sociopath she started out as. Plus, it’s really funny to watch Kristen Bell consistently emasculate Ken Marino.

J.K. Simmons (Leonard Stiltskin)

Long before J.K. Simmons was an Oscar winner, or even the guy in the Farmers insurance commercials, he popped up a couple of times on Party Down as Leonard Stiltskin, a vicious psychopath of a movie producer. Curses just sound better when they come out of certain people’s mouths, and Simmons is one of them. The funniest/scariest thing about Leonard Stiltskin is how close to reality the character actually is. Leonard loves you and thinks you’re amazing, right up until he doesn’t anymore.

Steve Guttenberg

Steve Guttenberg is one of many celebrities to play himself on Party Down, albeit a slightly exaggerated version. When Guttenberg forgets to cancel Party Down Catering’s services, he decides to invite the whole gang in and let them throw a party for themselves. Guttenberg gives advice on how to rise to the upper class, explains how a tank full of water could possibly be art, and even steals someone’s girl. He also looks really, really good considering Cocoon is 30 years old.

Thomas Lennon (Nick DiCintio)

Lt. Dangle himself makes an appearance alongside his former The State co-star Ken Marino as Nick DiCintio, a recently divorced man hosting a very…special…kind of party… Okay, it’s an orgy andno one else knows it. Lennon shines as the frustrated divorcee, trying to get everyone and anyone into the subtly titled “F**k Room”. Eventually, his frustration boils over, and that’s when everyone climbs into bed with him… kicking Megan Mullally out in the process.

Enrico Colantoni (Gordon McSpadden)

Veronica Mars’ dad did more than pop in for a guest spot, he popped out, going nude for a jump in the pool while alienating his image-conscious wife and their entire neighborhood in the process. “You’re already dead! Ordinary f*cking people!” he yells, quoting Repo Man while showing the economically depressed Party Down staff that a seemingly ideal material life isn’t always the gateway to contentment, among other things…

Kevin Hart (Dro Grizzle)

Long before Kevin Hart was figuratively the biggest comedian on the planet, he was Dro Grizzle, a rapper paid a stupid amount of money by J.K. Simmons’ Leonard Stiltskin to perform at his daughter’s 16th birthday. Of course, Dro never actually takes the stage, as Leonard’s daughter stays locked in her room for most of the night when none of the cool kids showed up. Hart spends the episode getting high with Ken Marino, sharing business advice and developing a strategy for opening his Soup’r Crackers.

Paul Scheer (Joel Munt)

When Party Down Catering is hired to work a huge event Roman soon discovers that his former writing partner — Joel Munt, who sold out years ago — is there, and that he actually landed the job to develop one of Roman’s favorite books for the big screen.

Basically, it’s Roman’s worst nightmare until Munt reveals that he’s in over his head and can’t give the book’s author the vision he wants. Roman takes pity on him and winds up giving him the idea that saves the movie, and more importantly, Munt’s job. Also, the wrong guy ends up drinking pee. Don’t even worry about it. Party Down Catering nails it again.

George Takei

Takei makes an appearance as a guest at the Stennheiser-Pong Wedding, a lovely gathering that somehow scheduled Party Down Catering, who have been banished to some kind of farmhouse, and Valhalla Catering, who did the banishing. Martin Starr’s Roman DeBeers, a self-proclaimed science fiction aficionado, spots the Star Trek actor and basically stalks him for the entire evening. Eventually, DeBeers nearly kills Takei by accidentally serving him food he’s allergic to. Oh my.

Josh Gad (Jeffrey Ells)

Before Josh Gad was seemingly everywhere, he was Jeffrey Ellis, the secretary, NOT president, of the California College Conservatives Union Caucus. Unfortunately, by the time Party Down is done with him, he’s a flag-burning commie, who also happens to be out of a job.

I want to point out that I started this list with Anna from Frozen and ended with Olaf. Let it go!