An opinion, every person has a diffrent view of what it is and there is no right or wrong awnser, exept the Jonas Brothers, who are a bunch of shit playing fags.
THe Best band ever is the band who is the Polar opposite of the Jonas Brothers.
The term used by everyone to define their favorite band on Urban Dictionary. Especially common among listeners of lesser-known bands and younger people with narrower tastes. It can never be known who the best band ever is, because it is subject to different preferences and opinions.
Teenage girl: GREEN DAY IS THE BEST BAND EVER!
Melodic death metal fan: Green day has no talent- you're just a conformist who likes to bandwagon on every hyped band with sex appeal. Clearly, Opeth is the best band ever.
Objective listener: Neither one of you is completely right- now please stop cluttering Urban Dictionary with your opinions!