Loved Once More With Feeling, and played the Cd over and over for a long time afterwards. I even bought the separate DVD despite having the box sets- I’m such a completist at times!
I found the Grey’s episode interesting as I think a lot of the actors have a mt background.
There was also an episode of Code Black billed as a musical episode although it only had a few numbers in it in the end are were part of a hallucination.
I thought the Grey's musical episode was great - shame they made a couple of the actors who really can't sing participate, but Sara Ramirez, Chandra Wilson and Chyler Leigh were excellent.
I loved the musical episode of The Flash. Victor Garber, Jesse Martin, Darren Criss and a whole cast of actors that sing. Combining MT songs and original numbers, it was a great stand alone episode.
There's an episode of Sleepy Hollow with Tom Mison's Ichabod Crane singing karaoke. A very creditable rendition of 'A young sailor cut down in his prime'
Not exactly TV Episode, but South Park the (Musical) Movie is brilliant, in my opinion. There have been some good songs in episodes too, but not enough classify one episode as a musical per say.
I loved Fringe and had completely forgotten about their musical episode 30's SciFi style complete with singing corpses until I googled musical TV episodes and was reminded of this.