My warrior is currently 90 with almost full malevolent. My dk is 85 on a shitty server, but Im getting bored AF on my warrior. So the question is, whats more fun for pvp, death knights, or warriors?
It's subjective. You already said you're bored of your Warrior (and our opinion won't magically change that) so I'd suggest just playing Death Knight some if that's a class you're interested in.