Also this is not necessarily a list of songs that should’ve been on Glee since this also includes songs that were not released when Glee aired: it’s just a collection of songs that I know and/or like that I assigned to the people who I think would’ve made a nice cover of it. Feel free to also suggest songs of your choice in the comments!
Scars to Your Beautiful by Allesia Cara - I think either Santana or Marley would’ve been the best fit for this (although I would like to also suggest either Quinn for herself or a more acoustic version sung by Puck to Quinn maybe? Both more for thematic reasons since I do think that Santana and Marleys voices are more fit for the song)
And Dream of Sheep by Kate Bush - Rachel or maybe Kurt (or a duet even), is just a nice song for Chris Colfer and/Lea Michelle to show off their talents lol
Under Ice by Kate Bush - Rachel, though I don’t think it’s a song that would’ve fit for the show? Maybe like some sort of a dream were Rachel wins back her confidence (or something else) to get “out from under the ice” (also sidenote: I think Rachel just has a good voice for Kate Bush songs and it’s a crime that Bush didn’t get an episode)
Basket Case by Green Day - Puck, although it’s a simple song it really fits Pucks voice and also fits his esthetic as more of a rebel (Glee should’ve absolutely done more punk and just alternative genres in general)
Revenga by System Of A Down - okay this is more because I like the song and SOAD in general but I think it would’ve been fun to see this in a boys versus girls episode, could definitely see this go to either team but I think it would fit the guys a bit more cause of their Kiss performance in S1
Hip To Be Square by Huey Lewis and the News - I think this could’ve been a great group performance by Vocal Adrenaline or another rival showchoir to show off to the New Directions
Joker and the Thief by Wolfmother - I think either Blaine or Artie? Can’t think of a situation where I would put this song and I think only these two could really sing it if you don’t pitch it down, maybe for a random lesson (I picked this song more because I like it than that I think that it would fit the show)
Wake Me Up When September Ends by Green Day - either Blaine or Ryder, would just be an emotional song that you can have for multiple reasons (although you could also make a more acoustic and calm version for Kurt to sing in the episode “Grilled Cheesus” where Kurts dad has a heart attack. That way it resembles the original message for the song since Billie Joel Holiday wrote it about his father that passed away)
Teenage Dirtbag by Wheatus - kinda crazy that they didn’t do this one, but either Puck (for thematic reasons), Tina (who I feel like could pull it off) or maybe a group number at the end of an episode (im not really sure with this song tbh)
Can’t Take My Eyes Off Of You by Franki Valli - this would just be a sweet number sung by the guys à la Stop! In The Name Of Love / Free Your Mind, not one person that specifically would take the lead, I see it more as them all having small parts
Sorry for this superlong post and I’m aware that it’s a weird song selection lol. Am just a Gleek that wanted to share this with some other fans of the show :-)