A new favorite fight of mine comes from Noragami. I only just watched the first season of Noragami in the viewing party two weeks ago, and the final fight between Yato and Rabo was a scene of raw awesomeness to me.
You have these two virtually immortal gods duking it out in a watery crater. Both of these gods of calamity share some history of violence and war, and their coming together shakes and disrupts the natural environment around them.
With Hiyori's memories on the line, Yato is fighting not just for himself, but for the girl that has come to mean so much to him.
Then Rabo goes and f*cks it all up by shattering Hiyori's memories, driving Yato into a killing rage, awakening the fighting spirit that Rabo was so desperately trying to draw out.
The swordplay was a real treat to watch. Even though these are gods, it didn't feel like it was over the top or forced. It felt like a proper battle between two accomplished warriors.
The only thing I didn't get (and still don't) is how Yukine in his sword form doesn't cut Yato's hand. There's no scabbard!