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.
Growing the Beard: Not that it was bad even when it was cancelled on UPN, but it really came into its own on [adult swim].
Foe Yay: There's some between Shannon and Brendon, most notably in the episode 'Bye Bye Greasy.' Shannon breaks into Brendon's room, comments on all his clothing on the floor, then this beauty happens.
Shannon: (grabs Brendon by the shoulders) I wanna sing, I wanna dance, let's make this happen!! (holds him.)
Brendon:W-Why are you putting your..arms on me?
Fenton also tends to get a bit over-touchy and protective of his 'Bren-Bren.'
Another Metalocalypse one: In "Temporary Blindness", Tucoo Von Laserstein sounds a bit like a prototype of Skwisgaar Skwigelf.
Tastes Like Diabetes: Walter and Perry's codependent relationship produces the most sickeningly sweet dialogue in any given episode.
Tear Jerker: The last episode where after the previous few episodes, as well as most of the final episode, have focussed on Brendon becoming less and less enthusiastic about his film-making, he explains his views to his friends. Then while lazily filming the scenery from the window of the car he's in, he accidentally drops the camera and it gets run over by another car. The final shots in the series are from the dying camera's POV.
Toy Ship: Jason apparently has plans to marry Melissa.
Apparently? He has an entire elaborate proposal set up, although ask him and he denies it.
There's also Brendon's brief relationship with Lani in "Yoko"
The Woobie: Melissa is often this when she interacts with McGuirk.
Especially in the mall scene during "Shore Leave".