YMMV / Eureka

• Anvilicious: "Blink", the Drugs Are Bad episode that thoroughly hammers in the point that schools and corporations may tacitly encourage people to turn to drugs to cope with the pressure to succeed, but at the end of the day doing drugs is never ok and anyone who does is a villain.
• Author's Saving Throw: A minor example, but after Kim's death characters still refer to her by her married name, Kim Anderson, for the first two seasons. Given her husband was a villain who used Laser-Guided Amnesia to manipulate and exploit her for years, it's unlikely she would want to keep his name. When a clone of Kim returns in Season 3, the character is given a maiden name to be referred to by, Kim Yamazaki.
• Awesome Music: Bear McCreary created much of the show's music, which in general is great, especially the main theme, composed by Mark Mothersbaugh.
• Awesome Ego: Nathan Stark. The only thing bigger than his intellect is his ego. He is one of the most brilliant characters on the show, so it's at least partially justified.
  Carter: "Does your ego fit in this building?!
  Stark: (nonchalantly checks the ceiling's height)
• Big-Lipped Alligator Moment: Henry gets a scene where he sings "She Blinded Me With Science" for his alternate timeline wife, not to mention the whole laser light show, Fargo DJ'ing from his office, and everyone dancing. Then again, this was Fargo's idea. Should we really be surprised? It was lampshaded: while trying to woo his alternate timeline wife, Henry realized that his alternative timeline self would already have used every play in his book, so he would have to do something completely out of character to impress her.
• Broken Base: The new timeline in Season 4. Some of the fandom enjoy the fact they're strangers in a strange land and felt the fresh dynamics helped to Win Back the Crowd after Season 3 suffered from some Seasonal Rot. Others feel that several relationships get Strangled by the Red String (Jo/New!Zane, Henry/New!Grace), and question that, if the last 4 years have been effectively retconned, why should we even care about these alternate timeline inhabitants, because it's not our Eureka anymore?
• Cargo Ship: As of "Momstronsity", S.A.R.A.H. and Sheriff Andy. Yes really; she even has shades of Tsundere.
• Crossover Ship: Claudia/Fargo in Crossing Over.
• Fan-Preferred Couple: Many prefer Jo/Taggart over Jo/Zane. A minor Broken Base occurred between fans of Jack/Tess and Jack/Allison. Jack/Nathan also has a passionate following.
• Friendly Fandoms:
  • With Warehouse 13 and Alphas, thanks to the Shared Universe.
  • A minor case with Fringe thanks to the odd Story Arc parallels in the later seasons. Both shows focus on an Alternate Timeline in Season 4 and begin Season 5 with a Time Skip to a Bad Future.
• Growing the Beard: While the first season is still well-liked, the show was definitely finding its footing. Stark and SARAH are absent from the pilot, the first few episodes tease that Beverly is involved in some nebulous evil conspiracy before essentially dropping her from the show until the season finale, it takes several episodes to get the ball rolling on the Myth Arc involving the Artifact, the Chekhov's Gun solutions to the Disasters Of The Week that would become a staple of the show are largely absent, and Fargo and Jo (who would both go on to have significant Character Development in later seasons) are fairly one-note side characters.
• Harsher in Hindsight: Henry and Beverly's conversation in "Force Quit" is a lot harsher once we find out that that timeline's Henry used to work with her
• Heartwarming in Hindsight: The end of the first episode of Season 2, Phoenix Rising sees Henry stating how Jack is now living in a timeline where he and Alison won't be together or meet the child they were having. Come the series finale, not only are Carter and Alison married but are expecting meaning that he will get to meet that child after all!
• Hilarious in Hindsight:
  • Elias Toufexis plays Adam Barlowe, an agent of The Consortium, a group dedicated to controlling all technological advancement in the world. In 2011, Toufexis plays Adam Jensen, a security officer and later Interpol agent who clashes with The Illuminati, a group with the exact same goal as The Consortium. He even uses the same voice for both roles.
  • Jonathon Young plays a scientist named Edison. A few months later, he would appear in Sanctuary as Nikola Tesla (might count as Actor Allusion depending on whether his casting in Sanctuary was already known at the time of the episode's writing).
  • This is not the last time Ming-Na Wen will be involved with a virtual reality.
  • When Carter's dream honeymoon house starts falling apart in The Honeymooners, he claims "I can fix it!" then instantly wonders where his hammer is^note the first trailer was shown two weeks before this episode aired, so it is dubious this could be a Shout-Out.
• Ho Yay: Jack and Nathan. Their rivalry can easily be interpreted as Belligerent Sexual Tension. There's also the fact that Jack's hallucination of Nathan in "The Ex-Files" inexplicably had the tendency to appear shirtless.
• Like You Would Really Do It: A handful of major characters have been Killed Off for Real over the course of the series, but when Allison is killed in the Season 4 midseason finale mere feet away from a Time Machine, it's no mystery that Jack is going to wind up back in time and Set Right What Once Went Wrong.
• Moral Event Horizon: It may seem odd to apply it to an AI that technically doesn't have morals unless programmed to, but the moment at the end of season five when Matrix!Carter uses Matrix!Jenna to try and get Allie not to set off the Z-wave bomb ("Mommy, I'm scared. Don't kill me. Stay with me.") is an absolutely horrific and cruel Player Punch that plays off of Children Are Innocent, and What If? to cement the viewers' hatred of the Matrix characters. The fact this is immediately followed up by seeing Matrix!Jenna matter-of-factly talk about wanting to see Mommy dead, helping Matrix!Carter strap Allie into the matrix, and heartlessly tell her good-bye makes it even worse.
  • Senator Wen killing Holly is an in-universe example. Not only did it make the viewers understand just how heartless and threatening a Big Bad she was, but it was this act which caused Beverly Barlowe's Heel–Face Turn thanks to Even Evil Has Standards...and this in turn led to Wen's Laser-Guided Karma Ironic Hell just to drive the point home.
• Retroactive Recognition: Michelle Creber played the one vocal member of Fargo's team at Galaxy Camp in "This One Time at Space Camp".
• Shocking Moments: The timeline getting rewritten in season 4. Specifically some of the changes it created such as Henry being an agent for the Consortium.
• Signature Scene:
  • The Shared Dream sequence between Jo, Fargo and Nathan that is an extended homage to The Mask of Zorro in "Noche de Sueños".
  • The last few minutes of "Founder's Day", where it is revealed that most of the cast wound up in an Alternate Timeline.
  • Carter's gleeful reaction when he learns that someone robbed a bank in "Up In The Air", and The Reveal of what actually happened shortly after.
  Carter: Andy?
  Andy: Yeah boss?
  Carter: You said there was a bank robbery?
  Andy: Yup. Someone stole it last night.
• Tear Jerker: More than once. "Once in a Lifetime" is particularly poignant.
  • Sheriff Carter having to hold back Henry from saving Kim, you can't help but feel for the man when he breaks down after failing to save the love of his life.
    • Carter looks almost as devastated, not only because of what he's lost as well but because of what he's had to do to his friend.
  • The death of Callister in "Right as Raynes", particularly Stark's reaction.
  • Stark's message in the logic diamond in "Show Me the Mummy". Sob. His death in "I Do Over" was gut-wrenching too, but also more of a shock. It was this episode that really made it hit home.
  • Fargo realising that Jack lied to him in "Force Quit" and that Holly never made it out of the simulation alive.
  • And a couple episodes later, when Holly (whose mind is still stuck in the matrix) realizes that they can't pull her out of the matrix because she's dead. Poor Holly. That entire storyline is made of tearjerker.
• They Wasted a Perfectly Good Plot:
  • The Shared Universe with Warehouse 13 and Alphas, in several ways:
    • All three series have their own Story Arcs that have far-reaching consequences, which could've had interesting effects on each other's arcs. They're rarely, if ever, mentioned.
    • EUReKA's first two seasons centered around The Artifact and The Consortium's attempts to control it. What does the crossover with Warehouse 13 center around? Fargo traveling to South Dakota to upgrade the Warehouse's computers, and afterwards Claudia visiting Eureka to study Global Dynamic's (classified) technology.
    • No crossover with Alphas ever happened.
  • Within the show itself, the Artifact. The writers clearly had major plans for it and there was a ton of foreshadowing about it being some kind of insane cosmic horror, but the original showrunner leaving forced the writers to drop it just as the subplot was getting interesting.
  • Henry erases Jack's memory of an alternate future without Jack's consent, and throughout Season 2, there are hints that Henry is riddled with guilt and Jack is ultimately going to learn what Henry has done. After Season 2, this plot point is never brought up again and Jack never learns the truth.
  • Nathan coming back from the dead in "The Ex Files". Since he is ultimately revealed as an illusion in Jack's head, Nathan is not able to interact with any other characters, most notably Allison (his former fiancé) and Fargo (who wound up with Nathan's old job).
• Trapped by Mountain Lions: Allison spends most of "Reprise" rescuing a man completely unrelated to the plot. subverted in that it was actually a fake memory to disguise some kind of Mind Probe put into her brain.
• What Does She See in Him?: While you could potentially rule it under All Girls Want Bad Boys and in fairness, he does have several seasons worth of good characterization, (and some rapidly condensed characterization in the fourth season), what exactly was it that initially attracted Jo to Zane? Even before they changed history, he still frequently came across as a bit of a douche bag to nearly everyone.
• The Woobie:
  • Henry. Nothing ever seems to go right for Henry, the hardest working person in the town.
  • While Jack is more of the Butt-Monkey/Chew Toy — i.e. most of the things that go wrong for him are played for laughs — he definitely has his woobie moments. The ending of "Unpredictable" is kind of heartbreaking: Allison is reconnecting with Nathan, his ex-wife is taking Zoe back to L.A. with her, and he's all alone in the middle of a crowded room.
  • Jo is staring to get this treatment in the fourth season. Her relationship with Zane has been erased, and she has to start from scratch with him. Plus everyone else thinks Zane's a menace, so she takes flack for trying to defend him. Then her house gets hit by a stray rocket. Now Zoe is starting up a relationship with Zane. That last one has her just barely avoid breaking down in public. She gets a wonderful new house... which Zane gleefully burns down under the influence of a song. She finally gets her man and a HappyEnding in the series finale.
  • Deputy Andy. He may be the only person in Eureka who can match Jack in terms of Butt-Monkey status, ends up having a fairly rocky relationship with Sarah, and is so earnest and desperate to help that it's near impossible to not pity him.