I LOVED UNPLUGGED.This breaks the rules but I don't care because the best thing that MTV ever did was MTV Unplugged. Just famous bands singing live with an acoustic backing and very intimate settings.
The most famous one probably being Nirvana's since it was one of the last things Cobain did on video before his death.
MTV filmed over 100 of them but only released 30. I really really want to know who the other 70 were. I also would've paid a lot of money to be at one of these shows back in the 90s.
This IMO is the best of them all: