I strongly support Gruvia as my fairy tail OTP. Yes their relationship may be inappropriate at times, even for me, but juvia really does love him and she shows it multiple times regardless of what Gray has been through. Her love is unconditional and there is no denying it whether you support it or not. I love that Gray has someone to love him, despite the little emotion he ever shows. At the end of series, if any ships end up being cannon, I hope it's this one.
My other fairy tail ship I support is Jerza, the tower of heaven arc was my absolute favorite and I've always loved and shipped them together. They were friends since they were kids and even then you could tell how much he cared for her. They both bring such an interesting dynamic to the story and I mean they're basically cannon anyway, thanks to Mashima.