"Shooting Star" brings gun violence into the halls of McKinley impressively, but possibly out of step with the series.
"Bad Reputation" is a Glee episode with high production value musical numbers and a relatable story.
"Sectionals" is a masterful Glee episode, but sacrifices some realism to serve their campy tone.
Mattress is a bizarre, atypical episode of Glee with a strangely sad tone.
"Mash-Up" has no singing mash-ups, but, given the story, is likely meant in the metaphorical sense.
With little music in "Vitamin D," Glee shifts focus to personal story arcs, mostly involving the adults.
Glee "Acafellas" has some big guest stars, and does great foreshadowing, but the music is weak.
Glee's "Showmance" is a high point, with great musical numbers, and shipper development galore.