When I think of great rivalries obviously the one that comes to mind is Batman/Joker. Kind of the creme de la creme. Where do you feel Bullseye/Daredevil ranks. It, to me, is a fantastic villain/hero rivalry. In fact, colorful and silly as it may seem, I've always felt Daredevil has an overlooked rogues gallery. Mr. Fear is cool, Owl has a ton of potential, and even some of his lesser known villains like Buschwacker and Bullit were quite interesting and often complicated and conflicted characters.
To me there is something quite special about their rivalry. Bullseye seems like he could honestly just be a henchman, or someone like Taskmaster, who functions as sort of an all purpose threat, but he really found a niche' with DareDevil, and thankfully he's not a copycat villain like Venom or Bizzaro. His "power" set is both different and complimentary. He's like DareDevil in many ways but also fundamentally different in many ways. Also, much like the Joker, he seems more interested in besting his foe rather than simply sucker punching him one day.
So where do you rate it? With so many classic stories and great moments in my opinion it might be almost as good as the Joker and Batman.