Spurs over arsenal - fans are less annoying.
My experience has been the opposite. Had a good mate at college, decades back, who was a lifelong Arsenal fan (his stepfather had played in the great team of the 1930s); he was always very respectful of City, as I was of his club. We both knew that we knew our football inside out. We both of us had a mutual semi-friend who was always very noisy about being a United fan. I'm pretty sure he'd never been anywhere near Old Trafford (of course), and knew nothing whatsoever about Manchester. Typical know-nothing rag supporting southern plastic.
With the mate in question we went and stood on the Kippax, along with his girlfriend (whom I'm still friends with, although she's not friends with him and hasn't been for a long time!), to watch us play his team (we won…) Once we went up the steps and got on the terraces, he just looked judiciously around at the stands, and quietly said “Yes, right… big club.” I stood on the North Bank several times with him to watch matches, not all of which involved City. Lost touch with him years back, but I often think of him, especially on nights like last night. I'm pretty sure he must have been at the Emirates. I can just imagine his gloomy face walking away from the stadium.
But even more recently, the Arsenal fans I've met in pubs and suchlike have been generally o.k., by and large.
By contrast, I've found Spurs fans uniformly full of themselves. Can't think why, since they haven't actually won anything within living memory. I suppose they just think, “We're Spurs, so we're big”.
Hate losing to them. Fucking hate it!
To cheer myself up I often watch highlights of the 2011 Dzeko Show at White Hart Lane. Or the more recent De Bruyne Show at the Etihad in December 2017.
By the same token, I have a strong preference for Everton over Liverpool. By and large, I've found the blue fans sound. The other lot are so full of themselves it's not true.
So as far as rivalries go, it depends entirely on the personal contact I've had with supporters, really.