"Sparks Nevada, Marshal on Mars": Earthman Sparks Nevada (Marc Evan Jackson) protects the Red Planet from robot outlaws, alien invaders, and other galactic threats. Typically the first segment of the show, and inspired it in the first place (it started out as a film script that the writers wanted to workshop).
"Beyond Belief": Frank and Sadie Doyle (Paul F. Tompkins and Paget Brewster) keep having to deal with the supernatural, though they'd rather just drink martinis all day. Typically the last segment of the show.
Affably Evil: Despite Jib Janeen's goals of destroying their cultures of the people he infiltrates, he's incredibly friendly and seems to genuinely enjoy the company of Sparks Nevada and co.
Jib Janeen: Oh my god, you guys. Felton. How much do you love him? He is a superstar. Okay, gotta jet! It has been real neat being part of your lives. Spaceship guys, I don't as well. Croach: you're really nice.
Croach: (flattered) Thank you.
A.I. Is a Crapshoot: At one point, Sparks Nevada tried to use a hologram program to act out fantasies where Croach the Tracker and The Red Plains Rider behave how he wanted them to. After a buggy patch update, the simulations decide to kill Nevada and make out.
Artistic License - History: Both Amelia Earhart: Fearless Flyer and The Cross-Time Adventures of Colonel Tick-Tock, oh so very intentionally so.
Brilliant, but Lazy: The Doyles are very effective occult investigators and monster hunters... if they get interested enough to counter their usual utter lack of concern about anything that is NOT (a) each other or (b) booze. The fact that they are continually drunk helps.
Frank and Sadie Doyle are expies of Nick and Nora from The Thin Man.
From the Sparks Nevada universe comes Pemily Stallwark, Champion of Punishment Soccer, a walking parody of The Hunger Games.
Fantastic Racism: Sparks Nevada is completely dismissive of Native Martian culture, and must constantly remind everyone that he's... from Earth.
Rebecca Rushmore despises Martians and claims that just hearing them talk gives her the shivers. Even when Croach saves her life by jumping in front of a blast that could have killed her, she wants to take a bath because Croach was too close.
Croach clearly does not think highly of humans either, taking many opportunities to point out how physically and mentally inferior humans are to Martians, and how shameful it would be for his behavior to be seen as resembling that of humans.
In the Sparks Nevada universe, everyone except Jupiterans (people from Jupiter) seem to be pretty bigoted against Jupiterans, who are pretty well known for their cunning ability to replace others. The writers and performers also admit that they feels that their writing has a real life anti-Jupiteran feel.
Jib shows this goes both ways when he claims that it would be a disgrace for his people if they let "mongrel genes" into the race.
"Freaky Friday" Flip: Sparks Nevada and Croach have their minds flipped by a "science gun" in one episode. Sparks has to contend with Croach's gross Martian physiology while Croach uses his new-found human emotions to try and get back with the Red Plains Rider.
Monster Clown: Nightmares the Clown, a recurring character in the Beyond Belief segments, and a reference to Pennywise the Clown from It.
Subverted in Sadie's case; she finds all clowns to be cute and funny, much to Nightmares' frustration.
Nice Job Breaking It, Hero: In the 2012 Christmas special, Frank and Sadie are visited by Christmas ghosts who have the wrong address. Through their actions, the Doyles manage to not only ruin the intended Scrooge's chance at redemption but cause his bitterness and hatred for Christmas in the first place.
When the Scrooge in question returns, the Doyles make it worse by introducing him to the wonders of alcohol as foreshadowed by Christmas Future's reveal that Scrooge's bartender is the only one who shows up to his funeral. Technically though, its the fault of the three ghosts for getting distracted by their romantic relationships instead of helping Scrooge at all.
No More for Me: In an alternate timeline, this is part of Sadie's backstory: she swore off drinking after she saw a ghost.
Noodle Incident: Frank and Sadie sometimes refer to "that time a bee got in here" as one of their more harrowing adventures.
Mundane Solution: Cactoid Jim is fated to become an evil dictator and destroy the universe if he becomes president. Sparks Nevada finally works up the nerve to assassinate him when:
Chicky: Hang on, hang on, hang on. I'm just spitballing, but what if Jim just dropped out of the race?
Plague Zombie: MurderMen can MurderMan people. They only have a few seconds to a few minutes before they are MurderManned, and become, well, MurderMen.
Poke the Poodle: Captain Laserbeam rushes to confront the Diebrarian to find that his sinister plot was to... purchase remaindered books and donate them to libraries so that children could read them! Rather than tell Diebrarian that his "evil" plan was actually noble, Captain Laserbeam just let himself be defeated and left.
San Dimas Time: In "The Cross-Time Adventures of Colonel Tick-Tock", when Queen Victoria repeatedly requires Colonel Tick-Tock to immediately leave to travel back in time to fix a problem. Lamp-shaded in one appearance where his wife Constance replies "Couldn't he leave at any time?" The Colonel explains "Quite the opposite. Were I to finish this biscuit, I would be far too late!"
One of his Adventurekateers admits that she's up-and-coming superhero Attagirl, but Captain Laserbeam wasn't paying attention. Even though that confession was one of his non-sequitur flashbacks later in the episode.
Snarky Non-Human Sidekick: Martian native Croach the Tracker criticizes Sparks Nevada at every turn, even as he works off his onus to Sparks for saving his tribe. This further plays into Sparks' resentment of Cactoid Jim, whom Croach praises up and down:
Croach: Cactoid Jim pronounced my name correctly on his first attempt!
Sommelier Speak: Occurs in "A Beyond Belief Valentines Day" after the Doyles discover wine.
Sound Defect: All over the place in the first "Beyond Belief" podcast, leading to such gems as "Dear, did you eventually hear a door opening?" and originating the running gag of Sadie occasionally providing the "clink!" sound effect herself.
Frank: Oh, how frequently we attend them! [...] Well, I was reading the auction magazine or brochure or program or whatever you call them at auctions, which we are constantly attending, it has been established.
Suspiciously Specific Denial: Banjo Bindlestuff is certainly not a millionaire! Banjo and his mentor Gummy will be quick to point this out! Even before anyone asks!
Took a Level in Badass: The Barkeep does this in "Good Jim." It helps that he was infused with phenomenal cosmic power.
Yet Another Christmas Carol: The 2012 Christmas episode's "Beyond Belief" segment has a Christmas Carol pastiche in which the ghosts get the address wrong and spend the whole night bothering Frank and Sadie.
The ghosts return to try and fix their mistake later... only for Christmas Present to discover its January and Christmas Past derailing the entire plot to confront Present and Future about their relationship.