Console war. I mean with music, it's understandable. There's variations in tastes and a lot of misinformation and blindness.
With Consoles it's just straight up "my console is better than urs" with no real reasoning. Objectively PC > PS4 > Xbone > Wii U. But some fanboys will have you believe that the order false in every sense. And people get so petty with things like "oh you have to pay for online now, so much for free" and PS4 fans are just like... "whatever. "
Console wars. You are literally arguing over things that don't even exist (game characters) and things that will not matter in a year's time (since they keep crapping out updates/new consoles)
The phone wars are pretty damn stupid too. I would say arguing over anything that is inanimate is childish and dumb.
That's one of the best!