They sing the fcuk outta this cover of Hey, Soul Sister.
Though the visual doesn't exactly match the awesomeness of the vocal. ["I'm so gansta, I'm so thug..."] -- No, Boo, you're not. But that's a good thing.
←Blaine (Darren Criss), is so adorable calling himself a gansta I'm a fan forever.
Download the full version and blast it on your iPod, then tell me it doesn't put a bounce in your day. Play it back to back with the original by TRAIN (below), which is itself a masterpiece (and a much better visual).
I could write a thesis on why GLEE is so necessary, and so cool.
Suffice it to say, the feeling that this song gives me is the essence of this deservedly award winning show -- which never ceases to make me misty, laugh and smile in every single episode.