These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Alas, Poor Scrappy: An in-universe example with Model Robot. After becoming increasingly more hostile to him throughout the show, Coiffio finally orders him to self-destruct. Which he does, taking Coiffio's entire ship with him.
Coiffio: ...Aw, shoot. Now I miss him.
Best Known for the Fanservice: Brenda. The way she seems to have more fanart than the others gives the vibe that she's mostly what the show is remembered for.
Bizarro Episode: However you define "sense" for this show, "Woke Up Drunk" makes none of it. It's suddenly a sketch comedy-parody involving the characters, where Gerald's father is apparantly a bear, his mother is one of the topless women from The Stinger of episode 3 wearing nothing but an apron, Young Man's bear companion dies after shooting Space Ghost and his ghost is a student at Gerald's school (which is also filled with palette swaps of him that have hair) with Coiffio as their teacher, an executive randomly shows up saying "Fund it" at points, there's a segment just focused on Brenda lying down with her ass in the air on a rotating platform, and among other things, it ends with three policemen appearing to have simulated sex with eachother. The main plot is only briefly cut to. [adult swim]'s website describes this as an electronic transmission that interrupts Gerald's quest, but that doesn't explain the sketches themselves.
Brenda has more fanart on Deviantart than anyone else from the show, although she doesn't have as much screen time as characters like Gerald or Uncle Grandfather and has zero (English) lines. Her outfit design probably helped contribute to that.