Probably not the thread for this, but I don't understand why the Gospel of John is considered so different from the others. B/c there's unique events? Big deal, all the Gospels have something that's not in the others. B/c no parables? Not really, there's still things like Jesus comparing himself to bread & water, etc. & it's not like he would've taught in just parables. There's still healings, the Passion, John the Baptist set-up, teachings, etc. B/c of the detail in it? So do Luke & Matthew.
I'm gonna deviate from the 'scholars' (biblical & pagan) & go ahead & say all of the Gospels are unique in their own way but have the similarities the essence is the same. However, that being said, if I was forced to say one is 'different' from the others, I'd say Mark.